- The definition of white-knuckle is something tense or something that causes fear and apprehension.
When an airplane has to make an emergency landing which caused extreme nervousness for the flight crew and passengers, this is an example of a white-knuckle landing.
Informal of or causing great fear, suspense, dread, etc.
Origin of white-knucklefrom the appearance of a hand clenched in fear
Characterized by tense nervousness or apprehension: a white-knuckle emergency landing.