Something tense, uncertain, frightening, very suspenseful, etc; cliffhanger: It was a white knuckle (1980s+)
verb: ''Just plain folks'' can white knuckle it around Mugello's tight curves
[fr the pallor of knuckles on an anxiously clenched hand]
Marked by tension, suspense, fear, etc: Invocations of a Soviet threat have become so common. He calls it ''the white-knuckle show''/ A genuine white-knuckle road (1980s+)