Two different meanings:
A: Some gadgetry in Halo 3 that throws a player either high up or far out into the distance, only to be sniped, skeet shot, or a battle rifle massage
in the back when he or she lands.
B: A bunch of jocks that take a scrawny or morbidly obese
high school student, one holds each arm, then they sling the 'ammo' into a crowd or another scrawny kid or morbidly obese person at
terminal velocity. Side effects to mancannoning someone can include, but is not limited to, temporary paralysis, permanent paralysis, eating concrete or other terrain, fractures, sprains, death, fights, embarrassment, disciplinary action, and commonly, unexpected gas.
A: LOLOLZ I MANCANNOND AND LANDED ON A TRIPINE IT WENT BOOM HEADSHOT FTW LOLFFFFFF.
B: I mancannoned Ned into fatty
just now.
It was funny until we found out he had to get his face reconstructed in
plastic surgery.