1. people who act as if they know everything; smart alecks
Usage: informal; plural of wisenheimer

Examples

• The teacher had to deal with several wisenheimers in her class.
• Those wisenheimers always have a sarcastic comment ready.
• Don’t be such wisenheimers – nobody likes a show-off.
• The wisenheimers in the back row kept interrupting the lecture.
• My older brothers were real wisenheimers when we were kids.
• The coach told the wisenheimers to stop making jokes during practice.