n.下颌;
例句:
His underjaw fell sideways open uncertainly.
他的下巴颏歪向一边,犹豫不定地咧着嘴.
A strong squre underjaw is a sign of firm character.
明显的方下巴是刚毅性格的标志.
She gave the rogue a smash on the underjaw.
她朝那流氓的下巴猛击一拳.