Definition of can openers:
(n) :
A device used to open tin cans, usually by slicing the lid off.
(n) :
(roller derby) A shoulder hit to the chest, usually accomplished while moving from a crouched to a standing position.
(n) :
(military, slang) An anti-tank munition or attack vehicle, that opens up armour like a tin can.
(n) :
(military, nautical, slang) A ramming maneuver, that opens up the target ship like a tin can.
(n) :
(slang) A tool for safe-cracking.