fire in (one's)/the belly

Passion and determination. I'm confident that Bill will get them to listen to our pitch—he has such a fire in the belly for this sort of work. It is a long, hard road to the major leagues, and you won't make it if you don't have a fire in your belly for the game of baseball. Constant rejection is just part of this industry, so you need to have a fire in the belly to make it here.

If you have fire in your belly or fire in the belly, you are ready to do something in a very energetic and passionate way. Ian has played with fire in his belly throughout his career. He accused the candidate of lacking fire in the belly. Note: You can also say that someone has a fire in their belly or a fire in the belly. He also has a fire in his belly. `I'm passionate about what I do,' he says.