One who changes their mind about what they believe or want to do very quickly and make themself seem stupid in the process
Jeff: Yeah man I don't think I want to go to the party I'm hella tired...
Jim: Alright dude I'll tell Courtney you aren't going, man she'l be missing you...
Jeff: Uhhh on second thought... I guess I'm not really that tired.
Jim: Man you are such a waggawopper.