1. a person who bites their fingernails, especially as a nervous habit
Usage: informal
2. a suspenseful event or competition with an uncertain outcome that causes anxiety or tension
Usage: informal

Examples

• My little brother is a chronic nailbiter whenever he gets stressed about school.
• The championship game was a real nailbiter that came down to the final seconds.
• She's been a nailbiter since childhood, especially during exams.
• That movie was such a nailbiter—I couldn't take my eyes off the screen.
• The election results were a nailbiter until the final votes were counted.