The definition of white-knuckle is something tense or something that causes fear and apprehension.(adjective)
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.
See white-knuckle in Webster's New World College Dictionary
Origin: from the appearance of a hand clenched in fear
See white-knuckle in American Heritage Dictionary 4
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