でかい顔かおをする

expression, suru verb (irregular)

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

Colloquial expression for behaving arrogantly or as if one is more important than others. Often used in negative contexts to criticize someone's attitude.

See also: 大きな顔をする · でかい顔する

• 彼かれは最さい近きん昇しょう進しんしてから、でかい顔かおをするようになった。

  Ever since he got promoted, he's been acting all self-important.

• あいつはいつもでかい顔かおをして、人ひとの話はなしを聞きかない。

  That guy always acts high and mighty and never listens to anyone.