夜や郎ろう自じ大だい

noun, na-adjective

overestimating one's own importance; throwing one's weight around without knowing one's limitations

A yojijukugo derived from a Chinese historical anecdote about the king of Yelang who boasted of his small domain's greatness. Used to criticize someone who is arrogant and ignorant of their own insignificance.

• 彼かれの夜や郎ろう自じ大だいな態たい度どには周しゅう囲いも呆あきれている。

  Everyone is fed up with his arrogant attitude, as if he were the king of Yelang.

• 夜や郎ろう自じ大だいのそしりを免まぬがれない。

  He cannot escape the criticism of being a Yelang who thinks too highly of himself.