1. a situation that makes you excited or worried
2. someone who has the habit of biting their fingernails
Origin and usage
The compound noun nail-biter is formed from the nouns ‘nail’ and ‘biter’. It was first used in the mid 19th century.
The noun nail-biter, which can also be spelled nail biter or nailbiter, refers literally to someone who habitually bites their nails. It also refers to a situation that is so tense it might make you want to bite your nails to ease the tension. This meaning is much more frequent in the corpus than the literal meaning and often occurs in the structure ‘a nailbiter of a …’. The second noun slot is often filled by words like game, match, competition, race, election or vote. The related adjective nail-biting collocates with nouns like suspense, cliffhanger, climax, finale and finish.
“Saturday’s nail-biter of a win over the Louisiana State Tigers was as excruciating a contest as I’ve ever seen.”
“On Tuesday, in a very high turnout election, the amendments were defeated in a nail-biter, 562 to 557.”
“A tight match contested in the searing heat of Tucuman, Argentina ended in a 1-1 stalemate, before the Australians held their nerve in the nail-biting shootout.”
cliffhanger, knife-edge, tinderbox