n. [ F. idiome, L. idioma, fr. Gr. 'idi`wma, fr. 'idioy^n to make a person's own, to make proper or peculiar; fr. 'i`dios one's own, proper, peculiar; prob. akin to the reflexive pronoun o"y^, o'i^, 'e`, and to "eo`s, 'o`s, one's own, L. suus, and to E. so. ] 1. The syntactical or structural form peculiar to any language; the genius or cast of a language. [ 1913 Webster ]

Idiom may be employed loosely and figuratively as a synonym of language or dialect, but in its proper sense it signifies the totality of the general rules of construction which characterize the syntax of a particular language and distinguish it from other tongues. G. P. Marsh. [ 1913 Webster ]

By idiom is meant the use of words which is peculiar to a particular language. J. H. Newman. [ 1913 Webster ]

He followed their language [ the Latin ], but did not comply with the idiom of ours. Dryden. [ 1913 Webster ]

2. An expression conforming or appropriate to the peculiar structural form of a language. [ 1913 Webster ]

Some that with care true eloquence shall teach,
And to just idioms fix our doubtful speech. Prior. [ 1913 Webster ]

3. A combination of words having a meaning peculiar to itself and not predictable as a combination of the meanings of the individual words, but sanctioned by usage; as, an idiomatic expression; less commonly, a single word used in a peculiar sense. [ 1913 Webster +PJC ]

It is not by means of rules that such idioms as the following are made current: “I can make nothing of it.” “He treats his subject home.” Dryden. “It is that within us that makes for righteousness.” M. Arnold. Gostwick (Eng. Gram.) [ 1913 Webster ]

Sometimes we identify the words with the object -- though by courtesy of idiom rather than in strict propriety of language. Coleridge. [ 1913 Webster ]

4. The phrase forms peculiar to a particular author; as, written in his own idiom. [ 1913 Webster ]

Every good writer has much idiom. Landor. [ 1913 Webster ]

5. Dialect; a variant form of a language. [ 1913 Webster ]

Syn. -- Dialect. -- Idiom, Dialect. The idioms of a language belong to its very structure; its dialects are varieties of expression ingrafted upon it in different localities or by different professions. Each county of England has some peculiarities of dialect, and so have most of the professions, while the great idioms of the language are everywhere the same. See Language.

{ } a. [ Gr. 'idiwmatiko`s. ] 1. Of or pertaining to, or conforming to, the mode of expression peculiar to a language; as, an idiomatic meaning; an idiomatic phrase. -- Id`i*o*mat"ic*al*ly, adv. [1913 Webster]

2. Of or pertaining to, or of the nature of an idiom{3}; having a meaning that is peculiar to itself and not predictable from general rules. [PJC]

a. Idiomorphous. [ 1913 Webster ]

a. [ Gr. 'idio`morfos of peculiar form; 'i`dios peculiar + morfh` form. ] 1. Having a form of its own. [ 1913 Webster ]

2. (Crystallog.) Apperaing in distinct crystals; -- said of the mineral constituents of a rock. [ 1913 Webster ]

a. [ Idio- + muscular. ] (Physiol.) Applied to a semipermanent contraction of a muscle, produced by a mechanical irritant. [ 1913 Webster ]