also: しばいげ
noun
theatricality; affectation; putting on an act
Refers to behavior that seems exaggerated, insincere, or overly dramatic, as if performing on stage. Often used critically to describe someone's manner or speech.
彼の謝罪には芝居気があって、本心とは思えなかった。
His apology had a theatrical quality and didn't seem sincere.
あの政治家の演説は芝居気が強すぎる。
That politician's speech is too theatrical.
Compound of 芝居 (play, drama) and 気 (spirit, mood, or air). The exact historical derivation is uncertain, but the word likely emerged to describe behavior reminiscent of stage acting.