The nickname given to any member of a sports team who neglects to wear fitting boxers or
compression shorts and proceeds to participaate in
jumping jacks. Their neglecence results in a the very noticable
flopping motion of their package as they continue jumping.
You: yo man aint u trippin about forgetting ur
compression shorts for practice
Friend: na its aight dude I'll just wear these
loose boxers
You: But we doin jumpin jacks right now, dude ur dick is floppin
everywhere. Ur a wacker jacks forreal