This is a variant of the verb phrase 'pussy out'. It means to back down from a commitment out of cowardice.
Mike always said he was going to go mountain biking with us, but then he pussed out.
by peter allen webb August 17, 2004
v. something you do when you talk all that smack but when it comes down to it you finally realize you were to scared to do it in the first place
She'd been talking dirty for weeks, but when I pulled out the schlong, she pussed out.
by BIG 60 July 13, 2004
v. when someone bails out of plans or refuses to participate for no other obvious reason than that they have no balls and/or are a pussy
He said he was coming, but I always knew he would puss out.
by key126 December 29, 2005