jump the gun

big gun

A person, group, thing, or course of action that is powerful, influential, or particularly effective.

eat one's gun

To commit suicide, especially by use of a firearm discharged into the victim's mouth.

fire the starting gun

To launch or trigger an event or situation.

give it the gun

To cause a specific vehicle to accelerate; to open the throttle of an engine.

go jump in the lake

Used to tell someone to go away, or that their request will not be met.

go jump off a building

Used to tell someone to go away, or that their request will not be met.

go jump off a cliff

Used to tell someone to go away, or that their request will not be met.

gun jumping

An act or instance of jumping the gun.