ˈ ̷ ̷ˌ ̷ ̷ noun
( -s )
Usage: often attributive
Etymology: blow back, v.
1. : an act of blowing back ; especially : escape backward of imperfectly burned gunpowder after a shot
2. : the action of a recoil-operated automatic or semiautomatic weapon that uses in its operation no locking or inertia mechanism to delay the rearward motion of the slide or breechblock ; also : a weapon using such an action