alarm
alarm — noun
1. a sound, light, or similar signal that tells people there may be danger or a ser
a sound, light, or similar signal that tells people there may be danger or a serious problem.
A loud alarm echoed through the station after someone left a bag behind.
alarm + location after a danger trigger
At midnight, the alarm sounded and every guest ran into the hotel car park.
an alarm sounded
Flashing red lights and an alarm told workers to leave the tunnel.
The ferry crew heard the alarm just as smoke rose from the engine room.
- sound the alarm
- hear the alarm
- false alarm
- fire alarm
- all-clear
a signal showing the danger has passed
Grammar Patterns
an alarm sounds
hear an alarm
false alarm
Usage Note
Common with verbs like 'sound', 'hear', 'ignore', and 'trigger'. Distinguish from sense 2: sense 1 is the warning itself, while sense 2 is the machine that produces it.
Common Mistakes
2. a piece of equipment that is made to give a warning signal when something is wro
a piece of equipment that is made to give a warning signal when something is wrong or unsafe.
The jeweller installed an alarm above the back window after two break-ins.
install an alarm
A silent alarm under the counter brought police to the bank.
silent alarm
Nina tests the house alarm every month before locking up the shop.
The museum alarm failed during the storm, so guards watched the doors.
- install an alarm
- burglar alarm
- smoke alarm
- alarm system
- security system
broader; may include cameras and locks as well as alarms
- detector
focuses on sensing smoke, gas, or movement, not the full warning device
Grammar Patterns
install an alarm
house alarm
car alarm
Usage Note
Often modified by a noun naming the danger or place, such as 'burglar alarm', 'fire alarm', or 'car alarm'. Distinguish from sense 1: here 'alarm' means the device, not the noise or light people notice.
Common Mistakes
3. a clock that you arrange to ring at a chosen time so it wakes you up.
a clock that you arrange to ring at a chosen time so it wakes you up.
Mina set her alarm for five-thirty before the sunrise hike.
set an alarm for + time
The alarm beside Ken's bed rang long before the first bus.
On school days, Rosa hides her alarm under a pillow.
After the power cut, my alarm showed the wrong time.
- set the alarm
- turn off the alarm
- bedside alarm
- alarm clock
- alarm clock
full form; more explicit than the shortened 'alarm'
- clock radio
a type of alarm clock with a radio built in
Grammar Patterns
set an alarm for + time
turn off the alarm
Usage Note
In everyday speech, people often say only 'alarm' instead of 'alarm clock'. Distinguish from sense 4: sense 3 is a separate clock by your bed, while sense 4 is a timed sound on another device such as a phone or watch.
Common Mistakes
4. a sound on a phone, watch, computer, or similar device that you program to go of
a sound on a phone, watch, computer, or similar device that you program to go off later.
Luca set a ten-minute alarm on his phone before the noodles boiled over.
set an alarm on + device
My watch alarm buzzed quietly during the meeting, and only I heard it.
watch alarm
The tablet alarm reminded Grandma Mei to take her heart medicine.
During the exam, Hana used her calculator alarm to track the final minutes.
- phone alarm
- watch alarm
- set an alarm
- morning alarm
Grammar Patterns
set an alarm on + device
phone alarm
watch alarm
Usage Note
Common with 'set' and with 'on' plus the device name. Distinguish from sense 3: sense 4 is a feature on another piece of electronics, not a separate clock made mainly for waking you up.
Common Mistakes
5. a sudden feeling of fear and worry when people think serious trouble may already
a sudden feeling of fear and worry when people think serious trouble may already be starting.
A wave of alarm spread through the crowd when the bridge began to shake.
a wave of alarm
Jo's voice rose in alarm as the toddler ran toward the road.
in alarm
To my alarm, the medicine bottle was empty on the kitchen shelf.
to my alarm
There was alarm in the village after dirty water came from the taps.
- widespread alarm
- deep alarm
- to my alarm
- in alarm
- calm
a state without fear or agitation
- reassurance
comfort that reduces fear
Grammar Patterns
in alarm
to someone's alarm
with alarm
Usage Note
Often appears in set patterns such as 'in alarm', 'with alarm', and especially 'to my/his/her alarm'. Distinguish from sense 1, which names an external warning signal rather than the feeling inside a person or group.
Common Mistakes
6. in North American fire reports, a label showing how much emergency help a fire n
in North American fire reports, a label showing how much emergency help a fire needs, with one alarm as the lowest level.
The warehouse blaze became a three-alarm fire before dawn.
number + alarm + fire
Local radio said the apartment fire stayed at one alarm.
stay at one alarm
By noon, crews had brought the factory fire down from four alarms.
A two-alarm fire closed the bridge and filled downtown with smoke.
- one-alarm fire
- two-alarm fire
- three-alarm fire
- four-alarm blaze
- fire level
plain explanatory term for the severity rating of a fire
- alarm rating
general label for the same graded scale in reporting
Grammar Patterns
one-alarm fire
two-alarm fire
three-alarm fire
Usage Note
Used mainly in North American news and emergency reporting. Usually follows a number and most often appears before the noun 'fire'. Distinguish from sense 6, which uses the same pattern figuratively for other kinds of trouble.
Common Mistakes
7. a troublesome situation described with the fire-rating pattern to show how serio
a troublesome situation described with the fire-rating pattern to show how serious it is.
When the singer vanished, the booking mess became a five-alarm crisis.
figurative number + alarm + crisis
Dad called the leaking roof a two-alarm problem after the rainstorm.
The missing passports turned our holiday morning into a three-alarm panic.
For the coach, two injured defenders on Friday was a one-alarm headache.
one-alarm + problem noun
- three-alarm crisis
- five-alarm mess
- two-alarm problem
- one-alarm headache
- minor issue
a problem too small to need urgent attention
Grammar Patterns
three-alarm crisis
five-alarm problem
one-alarm headache
Usage Note
This is an informal figurative extension of sense 5. It usually comes before nouns like 'crisis', 'problem', 'mess', or 'headache', rather than standing alone.
Common Mistakes
This expression means that people begin to feel worried or suspect that something is wrong.
When Sara saw the empty parking lot, alarm bells started ringing.
The sudden drop in sales made alarm bells ring for the manager.
alarm — verb
1. to make someone feel worried, shocked, or afraid because something seems dangero
to make someone feel worried, shocked, or afraid because something seems dangerous or badly wrong.
The dark stain on the baby's blanket alarmed both parents at once.
alarm + person
One engine losing power alarmed the pilot during the night flight.
Doctors were alarmed by the sudden rise in fever cases.
passive: be alarmed by + cause
The head teacher was alarmed when three children failed to reach school.
be alarmed when + clause
A sharp chemical smell alarmed workers in the paint factory.
- alarm staff
- alarm parents
- deeply alarm
- be alarmed by
Grammar Patterns
alarm + person
be alarmed by + noun
be alarmed when + clause
Usage Note
The object is the person or group that feels the fear, while the cause can be a noun phrase or a clause. Very often used in the passive, especially with 'by', 'at', or 'when'.
Common Mistakes
alarm — idiom
used when signs of trouble make people start to suspect that something is wrong and needs attention.
When sales fell for the third month, alarm bells were ringing in finance.
If a stranger asks for bank codes by text, alarm bells should start ringing.
Word family
Synonym discussion
Sense: noun/1
These words all relate to danger, but they point to different things. 'Alarm' usually suggests a signal that makes people react at once, often a sound or flashing light. 'Warning' is broader: it can be spoken, written, or signalled, and it often comes before the danger arrives. 'Alert' is common for official messages, phone notices, or a general state of readiness. 'Siren' is narrower still: it is the loud wailing sound itself, especially from emergency equipment or vehicles. 'Signal' is the most general word and does not always imply danger. Compare: 'The alarm went off in the hotel' focuses on the urgent warning, while 'The weather office issued a warning' focuses on information given in advance.
Common collocations
Nouns
- fire alarm
- burglar alarm
- car alarm
- alarm clock
- alarm system
Phrases
- set an alarm
- sound the alarm
- raise the alarm
- go off like an alarm
Prepositions
- alarm at something
- alarm in the building
- alarm on your phone
Etymology
English borrowed 'alarm' in the 1500s from French 'alarme', which came from Italian 'all'arme!', literally 'to arms!'. It began as a shouted call warning soldiers to get ready to fight. From that military cry, the meaning widened to any sign of danger, then to the fearful feeling such a sign causes, and later to devices such as fire alarms and alarm clocks.