An idiom meaning to try to pursue two goals at once and risk failing to achieve either (literally, 'to chase two hares').
彼は仕事と趣味を両立させようとしたが、結局二兎を追う結果になった。
He tried to keep both work and hobbies, but in the end he chased two hares and failed.
お金も時間も限られているのに二兎を追うのは無謀だ。
With limited money and time, trying to do both is reckless.
二兎を追うと、どちらも中途半端になりやすいから優先順位を決めよう。
If you chase two hares you'll likely do both half-heartedly, so set priorities.