definition

definition — noun

1. a sentence or short text that tells you what a word or expression means, especia

1.nounA2
Definition

a sentence or short text that tells you what a word or expression means, especially the one you find in a dictionary

Example

The dictionary's definition of 'courage' was too short to be helpful.

definition + of + [abstract noun]

Cyrus looked up the definition of 'photosynthesis' for his biology homework.

Common collocations
  • clear definition
  • definition of [word]
  • dictionary definition
  • give a definition
  • provide a definition
Synonyms
  • meaning

    broader — covers what something conveys, not only dictionary explanations

  • explanation

    can cover processes and reasons, not restricted to word meanings

  • gloss

    a brief or explanatory definition, often between the lines of a text

Grammar Patterns

definition + of + [word/phrase]

look up + the definition of + [word]

Common Mistakes

I looked up the define of this word.
I looked up the definition of this word.
'define' is a verb; 'definition' is the noun form.
What is the define of this term?
What is the definition of this term?
Use 'definition', not 'define', as the noun.

2. a clear description of what something is by stating its most important qualities

2.nounB2
Definition

a clear description of what something is by stating its most important qualities or its limits — for example, how a law decides who counts as an employee

Example

There is no single agreed definition of what makes an effective leader.

no single agreed definition of [abstract concept]

The legal definition of 'employee' varies from one country to the next.

legal definition of [term]

Common collocations
  • legal definition
  • working definition
  • definition of [abstract concept]
  • under [someone's] definition
  • broad/narrow definition
  • accepted definition
Synonyms
  • description

    more general — may list features without setting firm boundaries

  • delineation

    formal — emphasizes the act of marking limits precisely

  • specification

    technical — focuses on exact requirements or criteria

Grammar Patterns

definition + of + [abstract concept]

[possessive] + definition of + [noun]

by + [someone's] + definition

Usage Note

Common with possessives ('the government's definition', 'our definition') or adjectives describing the field ('legal definition', 'medical definition'). Distinguish from sense 1: sense 1 explains the meaning of a word; sense 2 describes the boundaries or essential nature of a concept, often in a specific field or context.

Common Mistakes

This is only his define of success.
This is only his definition of success.
Use 'definition', not 'define'.
The definition of intelligence is debatable.' (correct as is, but Taiwanese learners often add an unnecessary article: 'The definition of intelligence is the debatable.
The definition of intelligence is debatable.
No article before 'debatable'.)

3. used to say that something is necessarily true because of the very nature of the

3.nounB2
Definition

used to say that something is necessarily true because of the very nature of the thing itself — if you understand what the thing is, this fact follows automatically

Example

A circle is, by definition, a perfectly round shape with no corners.

by definition [comma] + formal definition of a category

Shirin's nursing job is by definition demanding, but she reads to her daughter each night.

Common collocations
  • by definition
  • is by definition
Synonyms
  • necessarily

    more general — does not carry the sense of 'by its very nature'

  • essentially

    overlaps in meaning but is less formal and less precise

  • inherently

    formal — suggests a quality built into something's character

Grammar Patterns

by definition, + [clause stating inherent property]

[noun] + is + by definition + [adjective/noun phrase]

Usage Note

Only used in the fixed phrase 'by definition'. The phrase is usually set off by commas or placed at the start of the sentence, followed by a characteristic that cannot be separated from the thing being described.

Common Mistakes

By definition, a bicycle have two wheels.
By definition, a bicycle has two wheels.
Third-person singular subject needs 'has'.
Cats are by definition animals.' (too obvious — 'by definition' is best used for a characteristic that is definitional but not trivial to all readers)
A rescue shelter is, by definition, a place for homeless animals.

4. the degree of sharpness and detail in a picture, video, or sound recording — how

4.nounB1
Definition

the degree of sharpness and detail in a picture, video, or sound recording — how clearly you can see edges, shapes, or hear individual sounds

Example

This television has excellent picture definition even in a bright room.

picture definition + [adjective]

The definition on the old video was too poor to make out people's faces.

Common collocations
  • high definition
  • low definition
  • picture definition
  • image definition
  • sound definition
  • definition setting
Synonyms
  • clarity

    broader — can describe text, thoughts, or explanations

  • sharpness

    narrower — mainly visual, emphasizes edge contrast

  • resolution

    technical — refers to pixel count or detail capacity, not perceived sharpness

Antonyms

Grammar Patterns

[adjective] + definition

picture / image / sound + definition

Usage Note

Frequently modified by adjectives of quality: 'high', 'low', 'poor', 'excellent', 'superb'. Used for both visual clarity (pictures, video) and audio clarity (sound reproduction). Think of it as a technical quality measure, not an opinion ('good' vs 'bad' are less common here than 'high' vs 'low').

Common Mistakes

This photo has a high definition.
This photo has high definition.
Uncountable noun; do not use 'a'.
This TV has a good define.
This TV has good definition.
'Define' is a verb; use the noun 'definition'.

5. the quality of having muscles that stand out clearly under the skin, usually fro

5.nounB2
Definition

the quality of having muscles that stand out clearly under the skin, usually from regular exercise and low body fat

Example

Hugo works out every day to improve the definition in his arms.

improve definition in [body part]

The bodybuilder's muscle definition was clearly visible under the bright stage lights.

Common collocations
  • muscle definition
  • good definition
  • improve definition
  • definition in [body part]
  • shoulder/arm/back/leg definition
Synonyms
  • muscle tone

    broader — includes firmness and tension, not just visual separation

  • delineation

    formal — the visible separation between muscle groups

  • muscle cut

    informal slang — common in bodybuilding communities

Antonyms

Grammar Patterns

[body part] + definition

definition + in + [body part]

definition + of + [body part]

Usage Note

Common in fitness, bodybuilding, and sports contexts. Uncountable — you cannot say 'a definition' or 'definitions' for this sense. Colloquial alternatives include 'muscle tone' (less sharp visual separation) and 'muscle cut' (very informal, bodybuilding slang).

Common Mistakes

She has a good definition in her stomach.
She has good definition in her stomach.
'Definition' is uncountable; no 'a'.
I want to get definitions in my arms.
I want to get definition in my arms.
Use the uncountable singular form.

6. the process or act of explaining exactly what a word, idea, or concept means — n

6.nounB1
Definition

the process or act of explaining exactly what a word, idea, or concept means — not the result itself, but the work of doing it

Example

The definition of key terms is the first step in writing a research paper.

definition of [terms] as a process

A clear definition of the problem helps the team find a better solution.

Common collocations
  • definition of [term]
  • definition of the problem
  • definition of roles
  • involve the definition of
  • require definition
  • process of definition
Synonyms
  • clarification

    broader — can mean making anything clearer, not just by defining

  • delineation

    formal — emphasizes marking boundaries, not just explaining meaning

  • determination

    more about deciding than explaining

Grammar Patterns

the definition of + [word/concept]

[possessive] + definition of + [term]

Usage Note

Often followed by 'of' + the thing being defined. Commonly used in academic, business, and professional contexts to describe the initial phase of establishing scope. Frequently occurs paired with verbs like 'involve', 'require', 'begin with'. Distinguish from sense 1: sense 1 is the product (the dictionary entry); sense 6 is the process.

Common Mistakes

The defining of key terms is important.' (grammatically fine but more natural:
The definition of key terms is important.')
The noun 'definition' is more natural than the gerund 'defining' in formal writing.
I need a definition of my goals.' (ambiguous — could mean sense 1 or sense 6)
I need to do a definition of my goals before I start.
Add process words like 'do a' or 'work on the definition of' to clarify sense 6.

7. an individual or object whose qualities make it a perfect illustration of its ki

7.nounC1
Definition

an individual or object whose qualities make it a perfect illustration of its kind — the best possible model of what that type is

Example

Sade's kindness to strangers was the very definition of compassion.

the very definition of [abstract quality]

That old house with a leaking roof is the definition of a fixer-upper.

Common collocations
  • the definition of
  • the very definition of
  • the definition of [abstract quality]
  • the definition of [a type of thing]
Synonyms
  • epitome

    formal — 'the epitome of' means the perfect example of a quality

  • embodiment

    suggests living representation, not just an example

  • personification

    only for people — suggests someone who perfectly represents an abstract idea

  • quintessence

    formal — the purest or most perfect form of something

Grammar Patterns

the very definition of + [noun]

the definition of + [noun]

Usage Note

Almost always appears in the fixed pattern 'the (very) definition of [noun]'. Adding 'very' before 'definition' adds emphasis and is extremely common in this sense. The noun following 'of' can be abstract ('courage', 'elegance') or concrete ('a fixer-upper', 'a disaster'). Singular only — do not use plural ('definitions') for this sense.

Common Mistakes

She is definition of a great chef.
She is the definition of a great chef.
Never omit 'the' before 'definition' in this sense.
He was the definition of bravery.' (correct but can be more natural with 'very':
He was the very definition of bravery.')
'Very' before 'definition' is a common and natural intensifier in this pattern.

Word family

Synonym discussion

Sense: noun/1

All three words relate to understanding, but they differ in scope and purpose. A 'definition' is a precise, formal statement of what a word or concept means — the kind you check in a dictionary. A 'meaning' is much broader: it covers the idea, message, or significance that something conveys, whether through words, symbols, actions, or even art ('the meaning of her smile'). An 'explanation' clarifies how something works or why something happened ('she gave an explanation for her absence'), which a definition typically does not do. An 'interpretation' is subjective — one person's reading of a text, event, or situation, which may differ from another person's ('my interpretation of the poem is different from yours'). Example: 'The dictionary definition of justice is straightforward, but different cultures have very different interpretations of what justice means in practice.'

Common collocations

Phrases

  • by definition
  • the very definition of
  • by someone's definition

Prepositions

Etymology

LatinOld FrenchEnglish

The word 'definition' comes from Latin 'definitio', meaning 'a bounding, a limiting, a setting of boundaries'. This was formed from 'definire', meaning 'to set bounds to, to limit', which in turn combined 'de-' (down, away) and 'finire' (to limit, end), from 'finis' (boundary, limit). English adopted the word through Old French 'definicion' in the 14th century. The sense of 'a perfect example' (sense 7) emerged much later, around the 18th century, through the logical idea that the defining features of something are the features that best represent it.