Definitions by Jigga JMO

jack-knife 

another term for a rude person, synonymous with asshole, jerk, dick, bastard

a way to curse without offending your grandparents

1) Dude, look at that jack-knife over there, what a douche!!
2) Quit being a jack-knife!!

jack-knife by Jigga JMO September 16, 2008