— nail-biter , n.
/nayl"buy'ting/ , n.
1. the act or practice of biting one's fingernails, esp. as the result of anxiety or nervousness.
2. Informal. nervousness: The announcement that the trade agreement had been signed ended a week of nail-biting on Wall Street.
adj.
3. Informal. causing nervousness: The nail-biting part of the canoe trip was through the stretches of white water.
[ 1890-95 ]