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4.
an adverb. stupid irrational, crazy, irrating confronting, person
that was one sepo muthafucka
did you see that cunt go all sepo on his ass
by dave December 22, 2002
 
1.
American. (Australian cockney rhyming slang.) From: Yank --> Tank --> Septic Tank.
Is he a Candian? No, he's a Sepo.
by The Linguist August 16, 2003
 
2.
American's
fucking sepos
by donny bonny May 25, 2003
 
3.
1. a name given to Americans that talk alot of shit, have monstrous horse teeth and complain about everything.

2. a term often used when talking to or about Jake Bryant
dont tell that sepo Jake that where going to the party
by darren June 27, 2004