ordnance vs gun

ordnance and gun both are nouns.

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

As nouns, ordnance and gun are synonyms defined as:

Other synonyms of ordnance include artillery, heavy weapon.

ordnance (noun)	gun (noun)
military supplies	the discharge of a firearm as signal or as a salute in military ceremonies
large but transportable armament	a weapon that discharges a missile at high velocity (especially from a metal tube or barrel)
	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)

ordnance (verb)	gun (verb)
	shoot with a gun