(slang) A prank in which a person's underpants are pulled up sharply from behind in order to wedge the clothing uncomfortably between the person's buttocks.
2003, Susannah Farfor, David Andrew, Hugh Finlay, Northern Territory (page 27)The white-bellied sea eagle is almost as big as a wedgie and handsomely marked in grey and white.
1989, Michael Moffatt, Coming of Age in New Jersey (page 86)Last year's juniors had wedgied last year's freshmen, and then each freshman victim had happily joined the patrol, its aficionados claimed.