A young man of dubious sexual orientation who lacks any discernible athletic ability and spends practically all his waking hours seeking the companionship of male athletes.
Jock 1 "Sylvester couldn't make the hoops team, but he never misses a game and shags loose balls and towels so he can get in the locker room. What up wit dat?"
Jock 2 "Don't pay him no mind, he's a jocksniffer. Notice how he's always dropping the soap in the shower?"