Slang term usually used to describe sawed off, double barreled shotguns which can only hold two shotgun shells at a time. one shell is inserted in each bore, allowing for two shots to be fired in rapid succession before it must be reloaded.
"nigga was sweatin me, so I pulled out my two shot and smoked him"
"I got a nickname for all my guns. A Desert Eagle that I call big pun. A two shot that I call 2-pac...." -- Qadir from the song "nickname"