slang A situation, experience, event, etc., that is marked or characterized by intense fear, anxiety, or stress. The last quarter of the game was a real white-knuckler, with the home team defending a two-point advantage against an offensive onslaught by their opponents. Driving so close to the edge of the cliff was a white-knuckler, to be sure.
1. n. a tense and nervous person. You white knucklers are just going to have to relax.
2. n. a suspenseful event, such as an exciting movie or a rough airplane flight. The movie was a real white knuckler.