Definition of idiom
The term idiom refers to an established expression or phrase that comprises two or more words. An interesting fact regarding the device is that the expression is not interpreted literally. The phrase is understood to mean something quite different from the individual words in the phrase. Alternatively, the phrase can be said to be interpreted in a figurative sense. Also, idioms vary in different cultures and countries.

Language examples in literature a bit difficult to bring to the mint. ”
(By Don Marquis)

The statement quoted above uses“ ray of light ”as an idiom meaning that some auspicious moment lurks behind the cloud or difficult moment.

Example # 2:
“American idioms lead me down the hall! "(From the character Ziva David, NCIS TV series)

Here, the word" idioms "is used as an idiom.

Example # 3:
" I worked the night shift with older people, which was really demoralizing, because older people don't get a shot in hell of ever dating. "(By Kate Millett)

In the excerpt quoted above," graveyard change "is used as an idiom.

Example # 4:
Kirk:" If we play our cards right, we may be able to find out when those whales are released. "

Spock:" How will playing cards help us? "

(Dialogue between the characters, Captain James T. Kirk and Spock in Star Trek IV: The Voyage Home, 1986)

Here," if we play our cards right "means" if we take our chances rightly. "

Example # 5:
" Shakespeare is credited with having coined more than 2,000 words, infusing thousands of existing words with electrifying new meanings and forging idioms that would last for centuries. A fool's paradise, "in one fell swoop," heart content, "" in a bind, "" send him packing, "" too much of a good thing, "" se game over ',' good luck ',' love is blind, 'to name a few.
(Straightening the Mother tongue: From Old English to Email, The Tangled History of English Spelling, by David Wolman)

T This passage highlights the collection of idioms used by Shakespeare in his plays. They are still used in everyday writing.

Example # 6:
"Idioms vary in 'transparency': that is, if their meaning can individual words. For example, the decision is fairly transparent when it comes to suggesting the meaning "make a decision", while the kick the bucket when it comes to depicting the meaning "die" is anything but transparent. “
(Longman Student Grammar of Spoken and Written English, by Douglas Biber, Stig Johansson, Geoffrey Leech, Susan Conrad and Edward Finegan)

The excerpt quoted above explains that idioms vary in their degree of transparency, that is, the extent to which an idiom reveals its true meaning .

Example # 7:
“Modal idioms are idiosyncratic verbal formations that consist of more than one word and have modal meanings that cannot be foreseen from the components (compare the non-modal idioms that make the difference). Under this heading we have [to], had better / best, would rather / sooner / so soon and would be [to]. “

The excerpt quoted above highlights the use and meaning of modal idioms.

Function of idioms
Writers and speakers use idioms generously. The purpose of this widespread use of idioms is to work out their language, make it richer and more flavorful, and help them do so to convey subtle meanings to their intended audience.

Non-idioms not only help make the language beautiful, they also make things better or worse by making the phrase good or bad. For example, there are several idioms that convey the death of a person in the most subtle meanings, and some do the same in very offensive terms. They are also meant to be accurate and more correct than the literal words and sometimes a few words are enough to replace a full sentence. They help the writer make his meaning clearer than he is so that he can convey maximum meanings through minimal words and also keep intact the multitude of meanings in the text.

It has also been seen that idioms convey not only subtle meanings, but also ideas that are not conveyed through normal and everyday language, and they keep the balance in communication. In addition, they provide textual coherence so that the reader can piece together a text they have walked through and extract meanings that the author conveyed.
Iambic Pentameter Illusion