1. a difficult question or problem that is hard to answer or solve
Usage: informal
2. a political speaker who travels around making campaign speeches
Usage: informal; political

Examples

• The final exam question was a real stumper that left most students confused.
• That riddle is such a stumper – I’ve been thinking about it for hours.
• The math problem proved to be a stumper for even the brightest students.
• The senator worked as a stumper, traveling from town to town during election season.
• The quiz show host enjoyed asking stumpers that challenged the contestants.
• This crossword clue is a real stumper – I can’t figure it out.