dog

dog — noun

1. a domesticated four-legged animal that lives with people and is kept for compani

1.nounA1
Definition

a domesticated four-legged animal that lives with people and is kept for companionship, protection, herding, or helping those with special needs.

Example

Mira takes her dog for a walk in the park every morning before breakfast.

dog as pet: take + dog + for a walk

The family's dog barked loudly when a stranger approached the front gate.

Common collocations
  • walk the dog
  • train a dog
  • feed the dog
  • dog owner
  • dog breed
  • guard dog
  • service dog
Synonyms
  • canine

    more formal or scientific; rarely used in everyday speech

  • pooch

    informal and affectionate; not used in serious contexts

Grammar Patterns

a dog

the dog

dogs

Usage Note

Can be used for any breed or mixed-breed animal; the term refers to both male and female dogs unless specified otherwise.

2. a man who behaves in a cruel, dishonest, or morally bad way.

2.nounB2
Definition

a man who behaves in a cruel, dishonest, or morally bad way.

Example

The landlord is a real dog — he raised the rent without fixing any of the broken pipes.

informal insult: a real dog

Amihan called her ex-husband a dirty dog after he lied about the money.

collocation: dirty dog

Common collocations
  • dirty dog
  • lazy dog
  • low-down dog
Synonyms
  • jerk

    common American English; slightly less severe

  • scoundrel

    more formal and old-fashioned

  • rat

    suggests betrayal or disloyalty specifically

Antonyms

Grammar Patterns

a dog

that dog

Usage Note

Often preceded by a negative adjective (dirty, lazy, low-down). Strongly negative; use with caution in polite conversation.

Common Mistakes

He is a dog' (to mean lazy).
He is a lazy dog.
the adjective before 'dog' is required in this sense to clarify the meaning.

3. a very offensive term for a person, most often a female, that insults their phys

3.nounC1
Definition

a very offensive term for a person, most often a female, that insults their physical appearance.

Example

The bully shouted an ugly dog remark at the new student, and the teacher sent him to the office.

offensive register: ugly dog

Caleb's grandmother was hurt when she overheard someone call her an old dog at the market.

Common collocations
  • ugly dog
  • old dog

Grammar Patterns

a dog

Usage Note

This is a highly offensive insult, especially when directed at a woman. It condemns the speaker more than the target. Avoid using it entirely.

4. an adult male of certain wild or domestic species, including dogs, foxes, wolves

4.nounB1
Definition

an adult male of certain wild or domestic species, including dogs, foxes, wolves, and otters.

Example

At the wildlife centre, the zookeeper explained that this fox is a dog and the smaller one is a vixen.

contrast: dog (male fox) vs vixen (female fox)

The dog otter is about a third larger than the female and has a broader head.

Common collocations
  • alpha dog
  • dog fox
  • dog otter
Antonyms
  • bitch

    the female of certain canines and other animals such as otters

  • vixen

    the female of a fox

Grammar Patterns

a dog

the dog

Usage Note

In the context of domestic dogs, the term 'dog' (male) is contrasted with 'bitch' (female). For foxes, 'dog' contrasts with 'vixen'. For otters, 'dog' contrasts with 'bitch' or 'sow'.

5. an informal, often friendly way of referring to a man, usually with an adjective

5.nounB2
Definition

an informal, often friendly way of referring to a man, usually with an adjective that describes a quality or situation.

Example

Élise smiled and said, "You old dog, I haven't seen you in years!" when she spotted her former classmate.

informal greeting: you old dog

Hao won two free plane tickets in the raffle, and his friends called him a lucky dog.

collocation: lucky dog

Common collocations
  • old dog
  • lucky dog
  • sly dog
  • jolly dog
Synonyms
  • chap

    British English equivalent; neutral to affectionate

  • guy

    the most neutral and common term; no adjective required

  • fellow

    slightly old-fashioned but still understood

Grammar Patterns

a dog

old dog

lucky dog

Usage Note

Almost always occurs with a preceding adjective (lucky, old, jolly, sly, etc.). The tone is friendly or teasing, never insulting. Compare with noun sense 2 (UNPLEASANT MAN) where the adjective is negative.

Common Mistakes

He is a dog' (meaning 'He is a friendly guy').
He is a funny old dog.
the adjective + 'old' pattern is typical for the friendly sense.

6. something that is poorly made, performs badly, or is of disappointing quality.

6.nounB2
Definition

something that is poorly made, performs badly, or is of disappointing quality.

Example

Sofia bought a cheap camera online, but it turned out to be a real dog — the photos were all blurry.

pattern: a real dog

That movie was a complete dog; the story made no sense and the acting was terrible.

Common collocations
  • real dog
  • total dog
  • complete dog
Synonyms
  • lemon

    used almost exclusively for defective vehicles

  • dud

    can apply to products or events; slightly milder

  • bomb

    American slang for a failed performance or product

Antonyms
  • gem

    something excellent or of high quality

  • winner

    informal; something that performs well

Grammar Patterns

a dog

that dog

Usage Note

Often preceded by 'real' or 'total' for emphasis. Common in American English for products, films, or vehicles that fail expectations.

Idioms

It means it is raining very heavily.

We stayed inside because it was raining cats and dogs.

Did you get wet? It was raining cats and dogs all morning.

An event designed to impress people and gain their support or money.

The company's product launch was just a dog and pony show.

Investors saw through the dog and pony show and refused to fund the project.

A situation where people compete fiercely and are willing to harm others to succeed.

In the business world, it's often dog eat dog.

They work in a dog-eat-dog industry where trust is rare.

A person who prevents others from enjoying something they themselves do not want or use.

He's a dog in the manger, hoarding resources he never uses.

Why be a dog in the manger? Let others use the equipment.

Something that has been done very badly or is a mess.

The report was a dog's breakfast, full of errors.

She made a dog's dinner of the presentation, confusing everyone.

An unhappy life filled with problems or unfair treatment.

The stray dog led a dog's life on the streets.

He complained that his job gave him a dog's life with no rest.

Everyone will have good luck or success at some point in their life.

Don't worry, every dog has its day, and yours will come.

She finally won the award; every dog has its day.

To argue or fight frequently and intensely.

My siblings fight like cat and dog over the TV remote.

The neighbors fight like cat and dog, always shouting at each other.

Once a person has a bad reputation, it is hard to change because others continue to blame or suspect them.

After the scandal, give a dog a bad name, and no one trusts him.

She made one mistake, but give a dog a bad name, and it sticks.

To become much worse in quality or condition.

The old neighborhood has gone to the dogs since the factory closed.

If we don't maintain the park, it will go to the dogs.

An alcoholic drink taken to cure a hangover from drinking too much the night before.

He ordered a beer as hair of the dog to feel better.

She swore by a bloody mary as the hair of the dog.

To be personally involved in a situation and have something to gain or lose from the outcome.

I don't have a dog in this fight, so I can be impartial.

The employees have a dog in the fight, so their opinions matter.

To avoid discussing a past issue that could cause trouble if brought up.

We decided to let sleeping dogs lie and not mention the argument.

It's better to let sleeping dogs lie than reopen old wounds.

Working or being treated extremely hard or harshly.

He worked like a dog all week to meet the deadline.

The interns were treated like a dog, with no breaks.

Very determined and refusing to give up on something.

The reporter was like a dog with a bone, chasing the story.

She stuck to the problem like a dog with a bone until she solved it.

To have no chance at all of succeeding.

He doesn't have a dog's chance of winning the race.

Without proper training, she hasn't a dog's chance of getting the job.

Feeling very ill, often with vomiting.

After eating bad seafood, I was sick as a dog all night.

She felt sick as a dog and had to stay home from school.

A situation where a less important part controls the more important whole.

In that company, the tail is wagging the dog, with interns making decisions.

When a small group dictates policy, it's the tail wagging the dog.

It is very difficult to change someone's long-established habits or methods.

My grandfather refuses to use a smartphone; you can't teach an old dog new tricks.

She tried to learn coding but gave up, saying you can't teach an old dog new tricks.

To allow someone to suffer or be punished unfairly, as if they are worthless.

The company threw the junior staff to the dogs to avoid blame.

He felt his boss threw him to the dogs during the audit.

If someone else can do a task for you, there is no point in doing it yourself.

Why keep a dog and bark yourself? Let the assistant handle it.

He does all the work himself, but why keep a dog and bark yourself?

dog — verb

dog — adjective

dog — adverb

dog — idiom

Word family

  • dogged
    adjectiveC1
  • doggedly
    adverbC1
  • doggy
    nounA2
  • dogless
    adjectiveB2
  • underdog
    nounB2
  • topdog
    nounC1
  • dog-like
    adjectiveB2

Synonym discussion

Sense: noun/1

Dog is the everyday word for the animal, used in all contexts from casual speech to formal writing. Canine is the scientific or clinical term, common in veterinary contexts ('canine teeth', 'canine influenza') but unnatural in everyday conversation — you would not say 'I walked my canine this morning.' Pooch is an affectionate informal term that implies warmth and familiarity ('The kids love the old pooch next door'). Puppy refers specifically to a young dog under about one year old; calling an adult dog a puppy can sound playful or mistaken. Use 'dog' as the default, 'canine' for technical references, 'pooch' for casual affection, and 'puppy' when age matters.

dogcaninepoochpuppy

Etymology

GermanicOld EnglishMiddle EnglishEnglish

Dog comes from Old English 'docga', a word of unknown origin that replaced the earlier Germanic word 'hund' (which survives in modern English as 'hound'). The shift from 'hund' to 'dog' happened in the early Middle Ages and is unique to English — related languages like German (Hund), Dutch (hond), and Swedish (hund) all kept the older root. The verb senses (to follow closely, to cause trouble) developed from the idea of a dog pursuing its target, appearing in the 1500s. The insult and informal uses (dirty dog, lucky dog) emerged in the 1800s as slang.