light a fire under

Idioms  

1. Also, build a fire under. Urge or goad to action, as in If we don't light a fire under that committee, they'll never do any work. This hyperbolic colloquialism uses light in the sense of “ignite,” a usage dating from the mid-1100s.

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Example Sentences

My great-uncle, a traditional yellow-dog Democrat who was born during the Depression and named for Franklin Roosevelt, predicted approvingly that Jackson would “light a fire” under the audience.

From Salon

“It will light a fire under us,” said Aiello, of the Wildlands Network, a conservation nonprofit.

From Los Angeles Times

Things move at a glacial pace when Celtic enter the transfer realm but if this powder-puff performance doesn't light a fire under the backside of the hierarchy - major shareholder, Dermot Desmond, in other words - then nothing will.

From BBC

As his Treasury Secretary Scott Bessent openly admitted, these threats are designed to "light a fire" under such stalled talks.

From BBC

She’s always going to her for advice, and Hamby always seems to know when to nurture and when to light a fire under Burrell.

From Los Angeles Times