n. [ L. expressio: cf. F. expression. ] 1. The act of expressing; the act of forcing out by pressure; as, the expression of juices or oils; also, of extorting or eliciting; as, a forcible expression of truth. [ 1913 Webster ]
2. The act of declaring or signifying; declaration; utterance; as, an expression of the public will. [ 1913 Webster ]
With this tone of philosophy were mingled expressions of sympathy. Prescott. [ 1913 Webster ]
3. Lively or vivid representation of meaning, sentiment, or feeling, etc.; significant and impressive indication, whether by language, appearance, or gesture; that manner or style which gives life and suggestive force to ideas and sentiments; as, he reads with expression; her performance on the piano has expression. [ 1913 Webster ]
The imitators of Shakespeare, fixing their attention on his wonderful power of expression, have directed their imitation to this. M. Arnold. [ 1913 Webster ]
4. That which is expressed by a countenance, a posture, a work of art, etc.; look, as indicative of thought or feeling. “The expression of an eye.” Tennyson. [ 1913 Webster ]
It still wore the majesty of expression so conspicuous in his portraits by the inimitable pencil of Titian. Prescott. [ 1913 Webster ]
5. A form of words in which an idea or sentiment is conveyed; a mode of speech; a phrase; as, a common expression; an odd expression. [ 1913 Webster ]
6. (Math.) The representation of any quantity or relation by appropriate characters or symbols, usually in a specific order. [ 1913 Webster +PJC ]
7. (Genetics) the production of products by a gene that cause the appearance of the corresponding protein or phenotype; -- of a gene or of an organism with a specific gene; as, the expression the beta-galactosidase positive phenotype, [ PJC ]
8. (Computers) a combination of characters linked by operators, occurring as part of the code of a computer program, which must be evaluated according to the rules of the computer language in order to produce a resulting value. [ PJC ]
In most programming languages, (a + b) is an expression indicating simple arithmetic addition, if the variables a and b are real numbers. Many other types of operation may be used in programs, and each set of symbols indicating an operation is an expression in that program. [ PJC ]
Past expression,
Beyond expression, beyond the power of description. “Beyond expression bright.” Milton. [ 1913 Webster ]