A male that is employed professionally as a middle school or high school "counselor", holding a position that is traditionally dominated by females.
A close synonym to the "mounselor" is the "murse", or "professional male nurse".
Kid 1: "Man I can't believe I got a dude counselor, kinda creeps me out yo!"
Kid 2: "Hahah, serious bro... You see the tits on my counselor?!? Makes me wanna get in trouble more, ya know?"
Kid 3: "Werd son, this some bull-ish! I gonna try to dump the "mounselor" and get in with ur girl asap!"