Here are some expressions that use the word “fire”.
1. Terminate employment
Bob was fired for incompetence.
2. Discharge a weapon
The policeman fired his gun at the fleeing suspect.
Fire away – do something without hesitation
I know you have many questions so fire away whenever you are ready.
Fire off – discharge; send (message) quickly
North Korea fired off several rockets at one time.
The president fired off several tweets in response to the news article.
Tom fired off several reasons why the proposal was not good.
1. inspire; excite
Before the game the coach fired up the team with his speech.
2. turn on [a machine]
I fired up my computer before making myself a cup of coffee.
Fire fight - a gun battle where opponents shoot at each other
The platoon got into a fire fight with insurgents while they were on patrol.
Be on fire – do something enthusiastically and successfully
The pitcher was really on fire and struck out every batter that came to the plate.
Play with fire – to do something that is dangerous and could cause harm
Unnecessarily antagonizing the boss is playing with fire.
Out of the frying pan and into the fire – describes a situation becoming worse
She did not realize that her subsequent comments caused her to jump out of the frying pan and into the fire.