light a fire under

verb

To motivate or encourage (someone) to start sooner or move faster.

“Let me see if I can light a fire under the waiter to get our order sooner.”

Ask AI about this wordChatGPTClaudePerplexityGoogle AIGrok

Meanings

verblight a fire under (third-person singular simple present lights a fire under, present participle lighting a fire under, simple past and past participle lit a fire under)

present singular third person lights a fire under · participle present lighting a fire under · participle past lit a fire under · past lit a fire under

  1. idiomatictransitiveTo motivate or encourage (someone) to start sooner or move faster.

    Let me see if I can light a fire under the waiter to get our order sooner.

Synonyms & antonyms

Also see
abetactuatebring aboutcheerdrawdriveencourageevokeexcitefomentgin upgoadigniteimpelincenseinciteinduceinflameinvokemotivatemovepromotepromptprovokepushquickenspark offspurspur onstimulatestirstir uptempturgewakewhetwhip up

Origin

Referring to a time when, if chimney sweeps were afraid to ascend a chimney, the fire would be lit under them in order to motivate them to climb to the top.

Full word history & related roots →
Cite this entry
APA

light a fire under. (n.d.). In WatkinsX Dictionary. Retrieved November 5, 2026, from https://dictionary.watkinsx.com/word/light%20a%20fire%20under

MLA

“light a fire under.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/light%20a%20fire%20under. Accessed November 5, 2026.

Chicago

WatkinsX Dictionary, s.v. “light a fire under,” accessed November 5, 2026, https://dictionary.watkinsx.com/word/light%20a%20fire%20under.

Source: light a fire under on Wiktionary, CC BY-SA 4.0.