Idiom

An idiom is a phrase whose meaning cannot be deduced from the literal definition, but refers instead to a figurative meaning that is known only through common use. In linguistics, idioms are widely assumed to be figures of speech that contradict the principle of compositionality; however, this has shown to be a subject of debate. It may be better to refer to idioms as John Saeed does: words collocated together happen to become fossilized, becoming fixed over time. [Saeed, John I. (2003), "Semantics". 2nd edition. Oxford: Blackwell. Page 60.] This collocation -- words commonly used in a group -- changes the definition of each of the words that exist. As an expression, the word-group becomes a team, so to speak. That is, the collocated words develop a specialized meaning as a whole and an idiom is born; for instance, "He really "threw me a curve" when on our first date he asked if I could pay for the dinner." Note, in some cultures, when a man and a woman are courting each other, the male is traditionally the one who takes up the bill or pays the bill; however, times change and in many modern societies, a lot of couples "go Dutch" (yet another idiom).

In the English expression "", for example, a listener knowing only the meaning of "kick" and "bucket" would be unable to deduce the expression's actual meaning, which is "to die". Although it can refer literally to the act of striking a specific bucket with a foot, native speakers rarely use it that way. It cannot be directly translated to other languages – for example, the same expression in Polish is "kopnąć w kalendarz" (to kick the calendar), with the calendar being as detached from its usual meaning as the bucket in the English phrase is. The same expression in Dutch is "het loodje leggen" (to lay the piece of lead), which is entirely different from the English expression, too. Other expressions include "break a leg" and "fit as a fiddle."

Another kind of idiom is the use of a single word to have multiple meanings, sometimes at the same time, and sometimes one meaning to be discerned from context. This can be seen in the (mostly uninflected) English language in the common use of the same word for an activity, for those engaged in it, and sometimes for a verb.

Idioms hence tend to confuse those not already familiar with them; students of a new language must learn its idiomatic expressions the way they learn its other vocabulary. Many natural language words have "idiomatic origins", but have been sufficiently assimilated so that their figurative senses have been lost.

Idioms and culture

An idiom is generally a colloquial metaphor — a term which requires some foundational knowledge, information, or experience, to use only within a culture where parties must have common reference. Idioms are therefore not considered a part of the language, but rather a part of the culture. As cultures are typically localized, idioms are often not useful outside of that local context. However some idioms can be more universally used than others, and they can be easily translated, metaphorical meaning can be more easily deduced.

While many idioms are clearly based in conceptual metaphors such as "time as a substance", "time as a path", "love as war" or "up is more", the idioms themselves are often not particularly essential, even when the metaphors themselves are. For example, "spend time", "battle of the sexes", and "back in the day" are idiomatic and based in essential metaphors. These "deep metaphors" and their relationship to human cognition are discussed by George Lakoff and Mark Johnson in their 1980 book "Metaphors We Live By."

In forms like "profits are up", the metaphor is carried by "up" itself. The phrase "profits are up" is not itself an idiom. Practically anything measurable can be used in place of "profits": "crime is up", "satisfaction is up", "complaints are up" etc. Truly essential idioms generally involve prepositions, for example "out of" or "turn into".

Interestingly, many Chinese characters are likewise idiomatic constructs, as their meanings are more often not traceable to a literal (i.e. pictographic) meaning of their assembled parts, or "radicals." Because all characters are composed from a relatively small base of about 214 radicals, their assembled meanings follow several different modes of interpretation - from the pictographic to the metaphorical to those whose original meaning has been lost in history. It may be a feature that helps everyday life.

Second language's English—using "idiom" to refer to language.

Further examples of idioms are "back seat driver", "feeding frenzy", or "right off the bat".

Parlance

"Idiom" can also refer to the characteristic manner of speaking in a language, also called its parlance. An utterance consistent with a language's parlance is described as idiomatic. For example, "I have hunger" is idiomatic in several European languages if translated literally (e.g. Dutch "ik heb honger", German "ich habe Hunger"; French "j'ai faim"; Spanish "tengo hambre"; Italian "ho fame", European Portuguese "tenho fome"), but the usual English idiom is "I am hungry".

This sense is also carried over to programming languages, where the former sense does not apply, as an expression or statement in a programming language can generally have only one meaning. For example, in Haskell, it is possible to apply a function to all members of a list using recursion, but it is more idiomatic to use the higher-order function map.

Computer science

In computer science, an idiom is a low-level pattern that addresses a problem common in a particular programming language. An idiom describes how to implement particular aspects of components or the relationships between them using the features of the given language.

For instance, in C source code one might see while(*a++ = *b++);, which copies characters, or whatever type the pointer references contain, from b to a until the null character ('