Yojijukugo
Definition and classification. The definition of is somewhat murky since the Japanese word can linguistically mean "compound", "idiom", or "phrase". Non-idiomatic. There exists a very large number — perhaps tens of thousands — of four-character compounds. A great majority of them are those whose meanings can be easily deduced from the literal definition of their parts. These compounds may be called "non-idiomatic" . For example, the compound word is a non-idiomatic . It is made up of four characters: , , , and . Alternatively, it can be regarded as consisting of two common two-character compounds: , and . Either way, the meaning of  the compound is clear; there are no idiomatic meanings beyond the literal meanings of its components. Below are a few more examples of non-idiomatic : Note that is itself a non-idiomatic four-character phrase. Idiomatic. By contrast, several thousands of these four-character compounds are true idioms in the sense that they have a particular meaning that may not be deduced from the literal meanings of the component words. An example of the highly idiomatic compound is: "Ocean-thousand, mountain-thousand" means "a sly old fox" or someone who has had all sorts of experience in life so that  they 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 one who has spent "a thousand years in the ocean and another thousand in the mountains". Many idiomatic 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 are typically limited to these "idiomatic" compounds of various origins. Chinese and Japanese origins of idiomatic. The Japanese are closely related to the Chinese , in that a great many of the former are adopted from the latter and have the same or similar meaning as in Chinese. Many other , however, are Japanese in origin. Some examples of these indigenous Japanese four-character idioms are: