four-character compound word; four-character idiomatic phrase
Refers to a compound word made of four kanji characters, typically idiomatic. Essentially synonymous with 四字熟語, but 四文字熟語 explicitly uses the counter 文字 (character). Commonly used in educational contexts.
See also: 四字熟語
Do you know any four-character idiomatic compounds?
The goal of this game is to form four-character compound words.
More common term for four-character idiomatic compounds. 四文字熟語 is a less frequent variant that explicitly includes 文字, and may be used to emphasize the character count or in educational settings.
Compound of 四 (four) + 文字 (character) + 熟語 (compound word, idiom). The term is a straightforward description of a four-character idiomatic phrase.