酢す豆どう腐ふ

noun

pretentious know-it-all; person who fakes expertise

Describes someone who acts like an expert but has only shallow knowledge. Often used critically or humorously. The literal meaning is 'vinegared tofu', but the idiomatic sense is the only modern usage.

• 彼かれはいつも難むずかしい言こと葉ばを使つかうけど、実じつは酢す豆どう腐ふだよ。

  He always uses difficult words, but he's actually just a pretentious know-it-all.

• あの酢す豆どう腐ふの話はなしは聞きく価か値ちがない。

  That know-it-all's talk isn't worth listening to.