noun A premature explosion in the cylinder of a gas or oil engine during the exhaust or the compression stroke, tending to drive the piston in the wrong direction.
noun An explosion in the exhaust passages of an internal combustion engine.
noun An explosion in other equipment.
noun Alternative form of back fire.
verb Of a gun, cannon, Bunsen burner, etc., to fire in the opposite direction, for example due to an obstruction in the barrel.
verb Of a reciprocating engine, to experience a premature ignition of fuel or an ignition of exhaust gases, making a popping sound.
verb To fail in a manner that brings down further misfortune.
His attempt to make money by importing luxury cars backfired horribly when fuel prices tripled.
verb To set a back fire (small, controlled fire to limit spread of a larger fire).