- 1[intransitive] backfire (on somebody) to have the opposite effect to the one intended, with bad or dangerous results Unfortunately the plan backfired.
- 2[intransitive] (of an engine or a vehicle) to make a sudden noise like an explosion compare misfire
NAmE//ˈbækˌfaɪər//Verb Forms present simple I / you / we / they backfire
he / she / it backfires
past simple backfired
-ing form backfiring