1. a person who acts as if they know everything; a smart aleck
Usage: informal; often used to show mild annoyance

Examples

• Don’t be such a wisenheimer and just listen to the instructions.
• The teacher got tired of the wisenheimer in the back row making sarcastic comments.
• My little brother is such a wisenheimer, always correcting everyone.
• She rolled her eyes at the wisenheimer who kept interrupting the presentation.
• The coach told the wisenheimer on the team to focus on practice instead of showing off.
• Every class has at least one wisenheimer who thinks they’re smarter than the teacher.