When a man realizes or finds out during mid sex that woman he is having sex with is not really a woman and in fact is a man who had a sex change operation. Like that one episode of South Park.
"Dude did you hear Joey got Mr.Garrisoned by some "chick" at the club?! He found out halfway during sex that "she" was a he!"

Mr. Garrisoned - def. Realizing halfway through intercourse that the woman you are with is a man
by Akx92 June 9, 2018
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gay teacher on southpark who eventually gets a sex change, usually seen with mr. hat
Mr. garrison likes to get his snooch pounded like any other woman.
by clarc31 January 19, 2007
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One fucked up motherfucker from South Park. He is the teacher of Stan, Kyle, Cartman and Kenny. He was gay as a male, and later, when he turns into a women via sex change, he becomes a lesbian. He's just gay no matter what sex he turns into. It's a fucking shitstorm. He also used to be obsessed with puppets. Mr. Hat was his original puppet lover, but he was replaced with Mr. Stick. Who knows what the hell Mr. Garrison did with those puppets. He's had relations with Big Gay Al, Mr. Slave, and guys he's somehow fooled into thinking he is a woman. Mr. Garrison created the Gay Tranny Paradox. If a gay man turns into a woman and becomes a "lesbian" is he gay or straight? I don't fucking know.
Mr. Garrison is a fucked up person.
by Stay Gold Ponyboy November 21, 2010
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