light a fire under (someone)

phrase

US, informal

: to cause (someone) to move or work more quickly and effectively

I've never seen him work so hard. Someone must have lit a fire under him.

Examples of light a fire under (someone) in a Sentence

Recent Examples on the Web

This is a program that needs someone who will light a fire under the defense, that will toughen up the Trojans on that side of the ball. — Mirjam Swanson, Oc Register, 29 Jan. 2026

Altman is trying to light a fire under his team to refocus on OpenAI’s core ChatGPT offerings over the coming weeks. — Sharon Goldman, Fortune, 18 Dec. 2025

May this light a fire under you to make your world a little more fragrant, one stick at a time. — Jenny Berg, Allure, 5 Dec. 2025

The Milwaukee 14, as the men became known, set out to light a fire under the local debate over the Vietnam War. — Chris Foran, jsonline.com, 17 Sep. 2025