fly
fly — verb
1. to stay and move in the sky by using wings (birds, insects) or engines (aircraft
to stay and move in the sky by using wings (birds, insects) or engines (aircraft, spacecraft)
A flock of geese flew south for the winter.
fly + adverb of direction (south)
The helicopter flew low over the houses in the village.
Small insects were flying around the garden on a warm evening.
A butterfly flew past Rohan's shoulder and landed on a flower.
fly + past (movement past something)
The paper plane flew across the classroom and hit the board.
- fly low
- fly overhead
- fly through the air
Grammar Patterns
fly + adverb/preposition of direction
Usage Note
This is the core physical sense. The subject is usually a living creature with wings or a man-made vehicle. Use this sense for describing the action itself, not for travelling as a passenger.
Common Mistakes
2. to travel somewhere using an aircraft as a passenger, or to cross a particular a
to travel somewhere using an aircraft as a passenger, or to cross a particular area in an aircraft
The Okonkwo family flew to Nigeria for the wedding.
fly + to [destination]
Imani flew from New York to Tokyo last spring.
fly + from [place] + to [place]
Linh and her family flew over the Alps on the way to Rome.
fly + over [geographic feature]
Haruto flew across the Pacific for the first time.
The couple flew business class to make the long journey easier.
fly + class type (economy, business, first class)
- fly to
- fly from
- fly over
- fly across
- fly direct
- fly non-stop
- travel by plane
more formal and less common in everyday speech
- go by air
slightly more formal, emphasises the mode rather than the journey
Grammar Patterns
fly + to/from [place]
fly + over [geographic feature]
fly + [distance/route]
Usage Note
Used when the speaker is a passenger. To describe operating the aircraft yourself, use sense 5 (PILOT). This sense commonly pairs with destinations, distances, or airline classes.
3. to choose and travel with a particular airline company when you go somewhere by
to choose and travel with a particular airline company when you go somewhere by plane
Linh and her parents usually fly Singapore Airlines when visiting their grandmother.
fly + [airline name] as object
Rohan prefers to fly Emirates because the service is excellent.
Ilan's company only allows employees to fly national carriers.
More travellers are choosing to fly budget airlines these days.
fly + budget airlines
Tamás flew Lufthansa to Frankfurt and connected from there.
- fly [airline name]
- fly with [airline name]
- travel with
more general, used with any transport company, not just airlines
Grammar Patterns
fly + [airline name]
Usage Note
The airline name functions as a direct object. This sense is used mainly in travel contexts when recommending or comparing carriers.
4. to move people or goods from one place to another in an aircraft, especially whe
to move people or goods from one place to another in an aircraft, especially when speed or distance makes other transport impractical
The charity flew medical supplies to the disaster zone.
fly + object + to [destination]
The company flew its engineers to the factory in Taiwan.
Fresh flowers are flown from Kenya to markets across Europe.
passive: are flown from [place] to [place]
Zayd's company flew him to the head office for a meeting.
The injured climbers were flown to a hospital in Kathmandu.
passive: were flown to [place] for emergency transport
- fly in
- fly out
- fly to
- be flown to
- airlift
more specific — implies emergency or military transport by air
- ship by air
used mainly for commercial cargo, not passengers
Grammar Patterns
fly + object + to [place]
passive: be flown + to [place]
Usage Note
Frequently used in the passive voice when the focus is on the people or goods being moved rather than the transport arrangement. The agent (the airline or pilot) is often omitted.
5. to operate and control an aircraft while it is in the air, especially as a train
to operate and control an aircraft while it is in the air, especially as a trained pilot
Asher learned to fly a small plane at the local airfield.
fly + aircraft type as object
The pilot flew the Boeing 777 through heavy rain.
fly + specific aircraft model
Aunt Rosa has been flying since she was eighteen years old.
fly (intransitive, person's profession or skill)
Lucas flew helicopters for the air force before he retired.
It takes years of training to fly a commercial airliner.
- fly a plane
- fly a helicopter
- learn to fly
- fly for [airline]
Grammar Patterns
fly + [aircraft type]
fly (intransitive, meaning 'to be a pilot')
Usage Note
When used intransitively ('Rosa flies for a major airline'), the subject is the pilot. When used transitively, the object names the specific type of aircraft.
Common Mistakes
6. to move, go, or pass very quickly in a particular direction, often with force or
to move, go, or pass very quickly in a particular direction, often with force or urgency
Élise flew down the stairs when she heard the phone ring.
fly + down [surface] (urgent movement)
The door flew open and the children ran into the garden.
fly + open (fixed expression for sudden opening)
A stone flew through the kitchen window during the storm.
Iker's backpack flew off the roof of the car as he drove away.
fly + off [surface]
The young pianist's fingers flew across the keys during the performance.
- fly open
- fly off
- fly down
- fly through
- fly past
- crawl
to move extremely slowly, often with difficulty
Grammar Patterns
fly + adverb/preposition (direction)
fly + adjective (result)
Usage Note
This sense describes physical speed. For time seeming to pass quickly ('time flies'), use the separate sense at verb/7 in the TIME PASSING group. Cannot take a direct object.
7. When a period of time goes by very quickly, often because you are busy or enjoyi
When a period of time goes by very quickly, often because you are busy or enjoying yourself, you say that time flies or the time flies by.
The afternoon flew by while Gabriel and Linh were painting the old kitchen.
Time flies when you are playing board games with close friends.
fixed expression: time flies
The three weeks of summer camp flew past much faster than Ishaan expected.
Yuki checked the clock and realised the morning had flown by already.
collocation: fly by
The hours flew past as they wandered through the narrow market streets.
- time flies
- fly by
- fly past
- pass quickly
more direct, less figurative
- race by
even faster, more dramatic
- drag
when time feels slow and boring
Grammar Patterns
fly + adverb (by / past)
time flies
Usage Note
Common in fixed expressions such as 'time flies' and 'the day / week / year flew by'. The verb is nearly always followed by an adverb like 'by' or 'past'.
Common Mistakes
8. If a flag, banner, or other piece of cloth is attached at one end to a pole or r
If a flag, banner, or other piece of cloth is attached at one end to a pole or rope and moves freely in the wind, it flies. When someone puts a flag in a high position on purpose, they fly it.
A row of colourful flags flew from the roof of the wedding venue.
The school flew the national flag at half-mast after the tragedy.
transitive: fly [flag] at half-mast
Small banners flew along both sides of the high street during the festival.
intransitive: banners / flags fly
Nadia climbed up and flew a blue flag above the beach to warn of currents.
Every embassy flies its own country's flag outside the main entrance.
- fly a flag
- fly at half-mast
- fly from a pole
- fly in the wind
Grammar Patterns
fly + flag / banner (transitive)
flag / banner + flies (intransitive)
Usage Note
Subject is usually a flag, banner, or sail. The transitive form (fly + flag) is used when a person or organisation chooses to display a flag on a pole or mast.
9. When news, opinions, or blame are exchanged rapidly among many people, often cre
When news, opinions, or blame are exchanged rapidly among many people, often creating excitement or tension, they are said to fly.
Rumours flew around the office after the manager resigned without warning.
collocation: rumours fly
Accusations flew between the two candidates during the heated television debate.
Wild stories flew across social media within minutes of the announcement.
Questions flew at the guest speaker from every corner of the crowded hall.
- rumours fly
- accusations fly
- fly around
- fly across
Grammar Patterns
rumours / accusations / questions + fly + adverb (around / across / between)
Usage Note
Subject is always an item of information or a type of speech — rumours, accusations, insults, gossip, questions — never a person. Common in present and past simple forms.
10. When an idea, plan, excuse, or product is accepted or works well, especially aft
When an idea, plan, excuse, or product is accepted or works well, especially after being tested or questioned, you say it flies.
The idea of a four-day working week did not fly with the company directors.
negative construction: not fly with
Vinícius knew his excuse would not fly with the strict head teacher.
The new advertising campaign flew past all expectations and doubled sales.
Obi's proposal to redesign the website flew with the marketing team.
- not fly
- fly with
- fly past expectations
- work
more general, neutral register
- be accepted
more formal, explicitly about approval
- take off
similar informal register, suggests quick success
Grammar Patterns
idea / plan / excuse + flies | does not fly
fly with + person/group
Usage Note
Chiefly informal and most common in negative or conditional contexts ('it will not fly', 'that might fly'). Subject is typically an idea, plan, suggestion, or excuse — not a person. Do not confuse with 'fly' meaning a person succeeds quickly (correct: 'the idea flew'; incorrect: 'he flew at his job').
Common Mistakes
11. To send a baseball rising through the air with a bat swing, usually so that a fi
To send a baseball rising through the air with a bat swing, usually so that a fielder can try to catch it before it lands.
Jessica flew out to centre field in the bottom of the ninth inning.
baseball: fly out to [field position]
The batter flew to deep left field, but Haruto made the catch easily.
With two outs, Vivek flew the ball to right field for the final out.
Élise flew the first pitch straight into the glove of the waiting shortstop.
- fly out
- fly to centre field
- fly the ball to
- hit a fly ball
more explicit, less concise
- pop up
suggests a short, high fly ball near home plate
- ground out
a different type of out where the ball stays low
Grammar Patterns
fly + adverb (to + field position)
fly + ball + adverb
Usage Note
A technical baseball term. The phrasal construction 'fly out' means the batter hits a fly ball that is caught by a fielder, resulting in an out. The intransitive form ('fly to left field') is more common in commentary than the transitive form ('fly the ball').
fly at
phrasal verbTo attack someone or something suddenly and with force.
The dog flew at the stranger when he approached.
She flew at him with her fists when he insulted her.
as the crow flies
idiomIn a direct straight line between two points, ignoring roads or obstacles.
The airport is only five miles away as the crow flies.
As the crow flies, the two cities are just 30 kilometers apart.
the bird has flown
idiomThe person who was wanted or looked for has already escaped or left.
When the police arrived at the hideout, the bird had flown.
We went to arrest him, but the bird had flown hours ago.
To do something without planning, relying on instinct and luck instead.
With no training, he flew by the seat of his pants and succeeded.
We had no map, so we flew by the seat of our pants.
fly the coop
idiomTo leave or escape from a place, especially one that is confining.
The prisoners flew the coop during the night.
As soon as the door opened, the cat flew the coop.
To show support for your country, group, or cause to encourage others.
Our team flew the flag at the international competition.
She waved the flag for women's rights at the conference.
fly high
idiomTo be very successful or achieve a high level of success.
The company has been flying high since its new product launch.
After winning the award, her career began to fly high.
To oppose or go against what is usual, expected, or accepted.
His decision flies in the face of all our advice.
That theory flies in the face of established science.
To suddenly become very angry, often without warning.
He flew into a rage when he heard the news.
She flew into a temper after losing her keys.
fly a kite
idiomTo test public opinion about an idea by suggesting it informally.
The politician flew a kite about raising taxes to see the reaction.
The company flew a kite for a new pricing model.
fly the nest
idiomTo leave home for the first time, usually as a young adult.
Both of her children have flown the nest now.
He flew the nest at eighteen to attend university.
To suddenly start talking about a different, unrelated topic.
During the meeting, he flew off at a tangent about his vacation.
Her mind went off at a tangent when she saw the painting.
fly off the handle
idiomTo suddenly become very angry, especially over something small.
He flies off the handle whenever someone criticizes his work.
She flew off the handle when she saw the mess.
To disappear completely or stop being relevant, often suddenly.
All our plans went out the window when it started raining.
His patience flew out of the window after the third delay.
go flying
idiomTo fall down, usually because you trip over something.
He went flying over the toy car left on the floor.
She went flying when she slipped on the wet tile.
go fly a/your kite
idiomA rude way to tell someone to go away and stop bothering you.
When he kept asking for money, she told him to go fly a kite.
If you don't like my idea, you can go fly your kite.
keep the flag flying
idiomTo represent your country or organization in a positive way.
Our athletes kept the flag flying at the Olympics.
She kept the flag flying for her company at the trade fair.
To attack someone physically or verbally with sudden force.
He let fly at the thief with a punch.
She let fly with a stream of angry words.
pigs might fly
idiomUsed to say that something is very unlikely to happen.
He'll finish on time? Yes, and pigs might fly!
She said she'd clean her room – pigs might fly!
time flies
idiomTime passes very quickly, especially when you are enjoying yourself.
Time flies when you're having fun with friends.
How time flies! It's already been a year since we met.
fly — noun
1. a common type of flying insect with a pair of transparent wings that produce a l
a common type of flying insect with a pair of transparent wings that produce a loud buzzing noise. These insects are often drawn to uncovered food and waste, and they can carry germs to people.
A fly landed on the edge of Wei's plate while she was eating lunch.
The kitchen needs a net over the window to keep flies out in summer.
countable: a fly / flies (plural); common collocation: keep flies out
Flies buzzed around the pile of fruit left on the market stall.
subject + verb: flies buzz/land/spread
Élise waved her hand to shoo a fly away from the bowl of rice.
A fly can carry germs from one place to another very quickly.
- swat a fly
- flies buzz
- fly spray
- keep flies out
- a fly landed on
- housefly
the most common type of fly found near human homes; more specific than 'fly'
Grammar Patterns
a/the fly
flies (plural)
Usage Note
Countable noun. When speaking generally about the species, the plural 'flies' is typical ('Flies are common in warm weather').
Common Mistakes
2. the front slit on trousers, shorts, or jeans that fastens with a zipper or butto
the front slit on trousers, shorts, or jeans that fastens with a zipper or buttons, often concealed beneath a fabric flap
Samir checked his fly was done up before leaving the restroom.
collocation: do up / zip up your fly; 'fly' = singular countable
The tailor sewed a new zipper into the fly of Dario's suit trousers.
Kian noticed his fly was open and quickly turned away to fix it.
common situation: fly is open / fly is undone
Some dress trousers have a button fly instead of a zipper.
The fly on those jeans is held closed by two metal buttons.
- do up your fly
- zip up your fly
- your fly is open
- button fly
- fly of [trousers]
- zipper
the fastener itself, not the opening; broader term used for any zipper
Grammar Patterns
the fly
your fly
fly of [trousers/jeans]
Usage Note
Usually singular. Frequently appears in the phrase 'your fly is open/undone' to politely tell someone their trousers need to be fastened.
Common Mistakes
3. a fake fishing hook wrapped in coloured thread, feathers, or fur so that it look
a fake fishing hook wrapped in coloured thread, feathers, or fur so that it looks like an insect or small creature, used to attract fish
Amani tied a small fly onto his fishing line and cast it into the river.
collocation: tie a fly / tie on a fly (prepare the hook)
The red-and-black fly looked so real that a trout bit it right away.
Cao spent the morning learning how to make his own fishing flies from feathers and wire.
collocation: make flies (craft the lures)
Different flies work best for different types of fish in this lake.
Ezra used a lightweight rod and a single fly to catch four salmon during the trip.
- tie a fly
- cast a fly
- artificial fly
- fly fishing
- dry fly
- wet fly
- lure
broader term for any artificial bait; 'fly' is a specific type of lure used in fly fishing
Grammar Patterns
a fly
flies (plural)
fly fishing
Usage Note
Frequently used in the compound 'fly fishing', which describes a method of fishing using an artificial fly as bait. The type of fly is often named after the insect it imitates, e.g. 'mayfly' or 'dragonfly pattern'.
Common Mistakes
4. a separate waterproof sheet that fits over the main body of a tent to keep rain
a separate waterproof sheet that fits over the main body of a tent to keep rain from coming through the inner fabric
After pitching the tent, Théo pulled the fly tight over the top to keep the night rain out.
collocation: pull the fly tight; purpose: keep rain out
Without the fly, the inside of the tent got wet during the storm.
Lucía packed the tent fly separately so it could dry out before the morning hike.
The fly should not touch the inner tent, or water may leak through.
construction note: fly must not touch inner tent to prevent leaks
Dylan replaced the old tent fly after it ripped in a strong wind last summer.
- tent fly
- rainfly
- fly sheet
- pitch the fly
- fly of the tent
- waterproof fly
- rainfly
common compound noun meaning the same thing, used especially in camping shops
Grammar Patterns
the fly
fly of [tent]
tent fly
Usage Note
Often called a 'rainfly' or 'tent fly' in camping equipment catalogues. It is pitched a few centimetres above the inner tent to create a gap that stops condensation and leaks.
Common Mistakes
5. in baseball, a ball struck by the bat that rises steeply into the sky, giving de
in baseball, a ball struck by the bat that rises steeply into the sky, giving defensive players time to run under it and attempt a catch
Ilan hit a high fly to centre field, and the outfielder caught it easily.
pattern: hit a fly + to [position]; common baseball usage
The shortstop ran back to catch a fly that was drifting toward the fence.
With two outs and the bases empty, a simple fly ended the inning.
The coach taught the young players how to track a fly from the moment it leaves the bat.
technique: track a fly ball with your eyes
Deep flies to right field often travel further because of the wind direction.
- hit a fly
- fly ball
- catch a fly
- fly to centre field
- pop fly
- deep fly
- ground ball
a hit that stays low and rolls or bounces along the ground
Grammar Patterns
a fly
fly ball
fly to [position]
Usage Note
Also called a 'fly ball'. Contrasts with a 'ground ball' (hit along the ground) and a 'line drive' (hit hard and straight). A 'pop fly' is a short, easy-to-catch fly, while a 'deep fly' goes far toward the outfield wall.
Common Mistakes
fly — adjective
1. slang for being very fashionable, attractive, or impressive in appearance or qua
slang for being very fashionable, attractive, or impressive in appearance or quality — for example, a fly outfit, a fly car, or a fly dance move.
Min showed up to the party in a fly leather jacket that everyone admired.
collocation: fly + (clothing noun)
The DJ's fly beats had the whole crowd dancing all night long.
Bilal bought himself a fly new pair of sneakers for the competition.
attributive use: fly + adjective + noun
Élise's dress looked absolutely fly at the award ceremony last Friday.
predicative use: look + fly
Tunde arrived driving a fly sports car with the top down.
- fly + clothes/outfit/jacket/shoes
- fly + car/ride
- fly + beats/track/moves
- look/feel/like + fly
Grammar Patterns
fly + noun
be + fly
Usage Note
This is dated US slang that saw a revival in hip-hop and pop culture. Avoid in formal writing or professional contexts. Typically used to describe appearance, style, or impressive objects rather than people's character.
Common Mistakes
2. (British informal) being alert, quick-witted, and unlikely to be tricked or dece
(British informal) being alert, quick-witted, and unlikely to be tricked or deceived — for example, a shopper who spots hidden fees, or a kid who knows not to trust a stranger's offer.
My granddad is pretty fly — he always spots when someone tries to overcharge him.
predicative: be + fly; British informal sense
You have to be fly to survive as a trader in that busy street market.
be + fly + to-infinitive for purpose
Jude was fly enough to notice the hidden charges before he signed the contract.
be + fly + enough + to-infinitive
The kids in that neighbourhood are so fly that no stranger could trick them.
so + fly + that-clause showing result
Reema's fly instincts told her the offer was too good to be true.
- be + fly
- pretty fly
- fly enough
- so fly that
- fly instincts/nature
- sharp
more common in American English; covers quick thinking and alertness
- smart
standard register; broader meaning including intelligence
- on the ball
idiomatic phrase meaning alert and quick to react
Grammar Patterns
be + fly
be + fly + enough + to-infinitive
so + fly + that-clause
Usage Note
Primarily British informal, though also used in other Commonwealth varieties. The American equivalent would be 'sharp,' 'smart,' or 'on the ball.' This sense describes mental alertness, not appearance — do not confuse with sense 1 (STYLISH).
Common Mistakes
fly — idiom
Fly River
idioma major river in Papua New Guinea that flows about 1,050 kilometres through lowland rainforests, swamps, and delta channels before emptying into the Gulf of Papua
The Fly River cuts through some of the largest untouched rainforests on Earth.
Élise studied how the Fly River carries sediment from the highlands to the coast.
Word family
Synonym discussion
Sense: verb/1
Fly is the general verb for moving through air using wings or an aircraft. Soar suggests rising high and floating smoothly, often with little effort — eagles soar on thermal currents. Glide implies smooth, effortless forward motion without flapping or engine power, like a paper plane or a hang-glider. Hover means staying in one place in the air, requiring rapid wing-beats (hummingbirds) or precise rotor control (helicopters). Flutter describes light, quick, irregular wing movements, typically of small insects or birds that stay close to the ground. For example: a butterfly flutters between flowers, a dragonfly hovers above the water, a hawk soars overhead, and a child's kite simply flies.
Common collocations
Etymology
The verb "fly" comes from Old English flēogan, which belongs to a family of Germanic verbs expressing movement through the air. It is related to Dutch vliegen and German fliegen. The core meaning — travelling through air using wings or an aircraft — has remained stable for over a thousand years, while newer senses (travelling as a passenger, flags waving, time passing quickly) developed by metaphorical extension.