gun vs trigger

gun and trigger both are nouns.

Word	Noun	Adjective	Verb	Adverb
gun	Yes	No	Yes	No
trigger	Yes	No	Yes	No

gun (noun)	trigger (noun)
the discharge of a firearm as signal or as a salute in military ceremonies	an act that sets in motion some course of events
a weapon that discharges a missile at high velocity (especially from a metal tube or barrel)	lever that activates the firing mechanism of a gun
large but transportable armament	a device that activates or releases or causes something to happen
a hand-operated pump that resembles a pistol; forces grease into parts of a machine
a pedal that controls the throttle valve
a professional killer who uses a gun
a person who shoots a gun (as regards their ability)

gun (verb)	trigger (verb)
shoot with a gun	release or pull the trigger on
	put in motion or move to act