expression
/ɪkˈspreʃn/ (bre, ipa) · /ɪkˈspreʃn/ (ame, ipa) · /ik-ˈspre-shən/ (ame, mw)
expression — noun
- expressionsingular
- expressionsplural
1. The act of communicating your thoughts, feelings, or opinions through speech, wr
The act of communicating your thoughts, feelings, or opinions through speech, writing, art, or other actions — for example, a poem that reveals a writer's grief, or a public march that shows people's anger about a new policy.
The teacher encouraged Min to find a creative expression for his ideas during art class.
find + adjective + expression for
Kwame believes that freedom of expression is essential for a healthy society.
freedom of expression (fixed phrase)
Sophia's painting was a powerful expression of the sadness she felt after losing her home.
The protest was widely seen as an expression of public anger over rising housing costs.
- communication
broader term covering all information exchange, not just personal feelings
- utterance
more formal and limited to spoken or written words
- manifestation
more formal; implies an outward sign of something abstract
- suppression
the act of preventing thoughts or feelings from being shown
文法句型
expression of [emotion/opinion]
find [adjective] expression in [medium]
freedom of expression
用法筆記
The uncountable form (expression) refers to the general ability or act — 'freedom of expression.' The countable form with 'an expression of' points to a specific instance — 'an expression of gratitude.' In formal writing, 'give expression to' can replace 'express' for a more literary tone.
常見錯誤
2. The way someone's facial features appear when they are experiencing a particular
The way someone's facial features appear when they are experiencing a particular emotion — a broad grin when delighted, or a furrowed brow when confused.
Elena's expression changed from confusion to understanding when she heard the answer.
expression changed from [emotion] to [emotion]
Rachel could tell from her father's expression that the news had upset him deeply.
tell from + possessive + expression
The little girl wore a sad expression after losing her favourite toy at the park.
Beatrix kept a completely neutral expression even though the question made her uncomfortable.
- look
less formal and broader than 'expression'; can also refer to appearance in general
- face
informal, as in 'make a face at someone'
- countenance
very formal and literary; refers to the whole facial appearance
- blankness
absence of any readable expression
文法句型
[possessive] + expression
expression + [preposition phrase]
用法筆記
When 'expression' refers to a facial look, it is almost always modified by an adjective describing the emotion (a worried expression, a blank expression). The phrase 'facial expression' is more explicit when the context could otherwise suggest sense 1.
常見錯誤
3. A set phrase or specific combination of words that speakers use in a given situa
A set phrase or specific combination of words that speakers use in a given situation or that belongs to a particular community — for instance, 'break a leg' in theatre circles, or 'bless you' after someone sneezes.
Christopher learned a formal expression to use when writing letters to the university office.
formal expression
The expression 'break a leg' is a strange way to wish actors luck before a show.
the expression '[phrase]'
Élise asked her teacher to explain an old-fashioned expression from the book they were reading.
Yael picked up a local expression for 'thank you' while travelling through the countryside.
文法句型
the expression '[phrase]'
expression + for/in [language/context]
用法筆記
Distinguish from sense 1: this sense refers to the word or phrase itself as a unit of language, not to the act of communicating. In dictionaries, 'expression' often appears in usage labels such as 'fixed expression,' 'idiomatic expression,' or 'colloquial expression.'
常見錯誤
4. In mathematics, a meaningful arrangement of numbers, letters, and operation symb
In mathematics, a meaningful arrangement of numbers, letters, and operation symbols (such as +, −, ×, ÷) that stands for a single numerical value — for example, '3x + 5' or '(a + b)²'.
The teacher asked Sora to simplify the algebraic expression on the whiteboard at the front.
algebraic expression
An expression such as '3x + 5' contains both a variable and a constant number.
expression such as [example]
Kabir solved the problem by substituting values into the mathematical expression step by step.
Priya simplified the algebraic expression in her notebook before the teacher collected the quiz.
文法句型
[adjective] + expression
expression + for [quantity]
用法筆記
In mathematics, an expression does NOT contain an equals sign — that would make it an equation. You can simplify or evaluate an expression, but you 'solve' an equation. Common in algebra, calculus, and computer programming contexts.
常見錯誤
5. In biology, the process by which information stored in a gene is converted into
In biology, the process by which information stored in a gene is converted into a visible or measurable effect in a living organism — for example, the way a gene tells cells to produce a particular pigment, resulting in brown eyes instead of blue.
The research team studied gene expression in plant cells exposed to extreme temperatures.
gene expression
Scientists found that diet affects the expression of genes related to long-term heart health.
expression of [a specific group of genes]
Dr. Okafor pointed at the protein expression data on her laptop screen and frowned.
Hamza's experiment measured the expression of a gene that controls flower colour in pea plants.
- transcription
the first step of gene expression, more specific
- protein synthesis
the overall process of which gene expression is a part
- gene silencing
the process by which a gene is prevented from being expressed
文法句型
[gene/protein] expression
expression of [gene]
用法筆記
This technical sense belongs primarily to molecular biology and genetics. Learners are most likely to encounter it in university-level science reading. 'Gene expression' is the most common fixed pairing — the word 'expression' alone may be ambiguous outside a biology context.