define

define — verb

1. To state the intended sense of a specific word, phrase, or symbol in a clear and

1.動詞及物B2
釋義

To state the intended sense of a specific word, phrase, or symbol in a clear and exact way.

例句

The dictionary defines 'photosynthesis' as the process by which plants convert sunlight into energy.

define + noun + as + complement

Gabriel struggled to define 'empathy' when his little sister asked him what it meant.

同義詞
  • explain

    broader; covers processes, reasons, and causes, not just word meanings

  • specify

    more precise; focuses on listing exact details rather than giving a general sense

  • clarify

    aims to remove confusion from something already partly understood

反義詞
  • obscure

    to hide or make the meaning hard to see

  • confuse

    to mix up meanings so the word becomes unclear

文法句型

define + noun + as + noun/phrase

define + wh-clause

用法筆記

Frequently followed by 'as' when providing the specific wording of a definition. The subject is typically a dictionary, textbook, or a person explaining a word's meaning. For setting the scope of roles or rules, use sense 2 (DELIMIT).

常見錯誤

The teacher defined me the word.
The teacher defined the word for me.
💡'define' does not take an indirect object without using 'for'.
The dictionary defines the meaning of the word.
The dictionary defines the word.
💡the word itself is the object, not its meaning.

2. To set the precise nature, scope, or boundaries of something, such as a rule, ro

2.動詞及物B2
釋義

To set the precise nature, scope, or boundaries of something, such as a rule, role, or duty, so that it is clearly understood.

例句

The contract clearly defines each partner's duties and how profits are shared.

define + duties / responsibilities

Aylin's role as project manager was defined in detail by the employee handbook.

passive: be defined + by + [document]

同義詞
  • delineate

    more formal; implies careful drawing of boundaries

  • determine

    focuses on fixing something after investigation; less about boundaries

  • specify

    stresses listing exact details rather than setting limits

反義詞
  • confuse

    to mix up boundaries so nothing is clear

  • blur

    to make the edges or limits fuzzy

文法句型

define + noun (role, scope, boundary)

be defined + by/as/in

用法筆記

Common in formal and academic contexts such as contracts, policy documents, and scientific research. Frequently passive: 'be defined + by/as/in'. Distinguish from sense 1 (STATE MEANING): here the object is a role, scope, or boundary rather than a word being given a dictionary sense.

常見錯誤

The contract defines about our duties.
The contract defines our duties.
💡'define' is transitive; do not add 'about' before the object.

3. To make the outline or physical form of something clearly visible, especially be

3.動詞及物C1
釋義

To make the outline or physical form of something clearly visible, especially because it stands out against a different background or surface.

例句

The mountain peaks were sharply defined against the orange sunset sky.

passive: be defined against [background]

Arjun could see the cathedral's outline clearly defined through the cold morning fog.

同義詞
  • outline

    more direct and common in everyday visual descriptions

  • silhouette

    verb form; specific to dark shapes seen against a lighter background

反義詞
  • obscure

    to hide the outline from view

  • blur

    to make the edges unclear or fuzzy

文法句型

be defined + against/in

define + noun (outline, shape, feature)

用法筆記

Common in visual descriptions and art. Frequently used with 'against' or 'in' to indicate the background that makes the outline stand out. Often passive, particularly with 'sharply' or 'clearly'. Distinguish from sense 2 (DELIMIT): here the object is a physical outline visible to the eye, not an abstract boundary.

常見錯誤

The artist defined the shape of the vase.' (ambiguous).
The artist defined the outline of the vase with a dark line.
💡in sense 3, be specific about the outline or edge, not the whole shape.