nail-biter

Noun

nail biter (plural nail biters)

1. (literal) One who habitually bites or chews their fingernails.
   • But Victor did not reveal any behavior disorder, did not pick his nose, did not suck his thumb, was not even a nail biter.1957 March 7, Vladimir Nabokov, chapter 4.3, in Pnin, Heinemann, page 90
2. (figuratively) A situation which causes anxiety, suspense, nervousness or discomfort.
   • It was a real nail biter waiting for the test results.

   Synonyms:

   cliffhanger