1. a person who pretends to know everything or acts as if they are very wise
Usage: often derogatory

Examples

• Don’t be such a wiseacre and admit you don’t know the answer.
• The classroom wiseacre always had a sarcastic comment ready.
• He’s a real wiseacre who thinks he can solve everyone’s problems.
• The wiseacre in the meeting kept interrupting with unhelpful suggestions.
• She rolled her eyes at the wiseacre’s latest know-it-all remark.
• Nobody likes a wiseacre who acts superior to everyone else.