Yojijukugo — four-character idioms

Yojijukugo (四字熟語) are idioms compressed into exactly four kanji — a whole observation about life in a single compound word. 一石二鳥 is "one stone, two birds"; 十人十色 is "ten people, ten colors" — to each their own. Many arrived from classical Chinese literature centuries ago, and Japanese has been coining its own ever since.

They read with Sino-Japanese (on'yomi) readings and range from everyday essentials — 一生懸命 (with all one's might) is one, even if nobody thinks of it as literary — to elegant set pieces deployed in speeches, essays, and exam questions. Learning them pays twice: each one teaches four kanji in a memorable package.

The list below is every word tagged as a four-character idiom in the dictionary. Sort it by frequency to start with the ones you'll actually hear, or shuffle for serendipity.