Four-character Idiom

 Yojijukugo (四字熟語, Yojijukugo "four character compound word") is a Japanese lexeme consisting of four kanji, or "Chinese characters". English translations of yojijikugo include "four-character compound", "four-character idiom" (Chinese chengyu 成語), or "four-character idiomatic compound".

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 The definition of yojijukugo is somewhat murky since the Japanese word jukugo (熟語, literally "ripe/mature/popular word") can linguistically mean "compound", "idiom", or "phrase".

 Yojijukugo in the broad sense of the term simply means any Japanese compound words consisting of four kanji characters. In the narrow or strict sense of the term, however, the term refers only to four-kanji compounds that have a particular (idiomatic) meaning that cannot be inferred from the meanings of the words that make them up.

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 By contrast, several thousands of these four-character compounds are true idioms in the sense that they have a particular meaning that is different from the meanings of the component words. An example of the highly idiomatic compound is:

• 海千山千 umisenyamasen (umi ocean + sen thousand + yama mountain + sen thousand)

Ocean-thousand-mountain-thousand means a sly old fox or someone who has had all sorts of experience in life so that s/he can handle, or wiggle out of, any difficult situations through cunning alone. This meaning derives from an old saying that a snake lives in the ocean for a thousand years and in the mountains for another thousand years before it turns into a dragon. Hence a sly, worldly-wise person is referred to as an ocean-1000-mountain-1000 person.

Many idiomatic yojijukugo were adopted from classical Chinese literature. Other four-character idioms are derived from Buddhist literature and scriptures, old Japanese customs and proverbs, and historical and contemporary Japanese life and social experience. The entries in the published dictionaries of yojijukugo are typically limited to these idiomatic compounds.

Based on the article "Yojijukugo" from Wikipedia
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