backfire
UK: ˈbækfaɪə | US: ˈbækfaɪər
vi. (of a plan or action) To have the opposite effect of what was intended, often causing harm.
vi. (of an engine or vehicle) To emit a loud noise due to improper combustion of fuel.
n. An instance of a plan or action producing unintended negative consequences.
The word "backfire" originated in the early 19th century, initially describing the explosive noise produced by an engine when unburned fuel ignites in the exhaust system (literally "fire shooting backward"). By the late 19th century, it evolved metaphorically to describe plans or actions that rebound negatively on their originator, mirroring the mechanical concept of reversed force. The morpheme "back" retains its Germanic root meaning "reverse direction," while "fire" derives from Old English "fȳr," referring to combustion.
The marketing campaign backfired when customers found the ads misleading.
His attempt to embarrass his colleague backfired, making him look petty instead.
The old truck backfired loudly as it struggled up the hill.
Strict censorship laws often backfire by fueling public dissent.
The policy intended to reduce traffic congestion backfired, creating longer delays.