gun vs shoot

gun and shoot both are nouns.

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

As verbs, shoot is a hypernym of gun; that is, shoot is a word with a broader meaning than gun:

Other hypernyms of gun include blast.

gun (noun)	shoot (noun)
the discharge of a firearm as signal or as a salute in military ceremonies	the act of shooting at targets
a weapon that discharges a missile at high velocity (especially from a metal tube or barrel)	a new branch
large but transportable armament
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)	shoot (verb)
shoot with a gun	give an injection to
	produce buds, branches, or germinate
	measure the altitude of by using a sextant
	record on photographic film
	make a film or photograph of something
	utter fast and forcefully
	fire a shot; release
	hit with a missile from a weapon
	score
	spend frivolously and unwisely
	force or drive (a fluid or gas) into by piercing
	throw or propel in a specific direction or towards a specific objective
	throw dice, as in a crap game
	variegate by interweaving weft threads of different colors
	run or move very quickly or hastily
	move quickly and violently
	send forth suddenly, intensely, swiftly
	cause a sharp and sudden pain in
	kill by firing a missile
	emit (as light, flame, or fumes) suddenly and forcefully