light a fire under someone

light a fire under (someone or something)

To motivate someone or something to take action. The deadline really lit a fire under us—we never would have gotten all that work done otherwise. Something must have lit a fire under Jenna—she has really started taking her schoolwork seriously.
See also: fire, light
Farlex Dictionary of Idioms.

light a fire under someone

mainly AMERICAN
If you light a fire under someone, you force them to act with more energy or to do something better. They need to improve their technical research and light a fire under their marketing team. It's hard to light a fire under people who don't think anything is wrong. Note: There is a story that some American farmers in the early part of the 20th century used to light fires under particularly stubborn mules that were refusing to move, in order to make them do so.
See also: fire, light, someone
Collins COBUILD Idioms Dictionary, 3rd ed.

light a fire under someone

stimulate someone to work or act more quickly or enthusiastically. North American
See also: fire, light, someone
Farlex Partner Idioms Dictionary
See also:
  • light a fire under
  • light a fire under (someone or something)
  • start a fire under (someone or something)
  • build a fire under (someone or something)
  • a fire under (someone or something)
  • draw a bead on (someone), to
  • keep after
  • keep after (someone or something)
  • put a bomb under
  • put a bomb under (someone or something)