でかい顔かおする

expression, suru verb (irregular)

act self-importantly; be arrogant; throw one's weight around

Colloquial expression; literally 'make a big face', used for someone acting superior or overbearing. Often implies a temporary attitude rather than a permanent trait.

See also: 大きな顔をする

• 彼かれは最さい近きん昇しょう進しんしてから、でかい顔かおしてるよね。

  Ever since he got promoted, he's been acting all high and mighty, hasn't he?

• あいつ、先せん輩ぱいの前まえででかい顔かおするなよ。

  Don't go acting all self-important in front of the senior members.