ordnance vs cannon

ordnance and cannon both are nouns.

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

As nouns, cannon is a hyponym of ordnance; that is, cannon is a word with a more specific, narrower meaning than ordnance:

Other hyponyms of ordnance include field artillery, field gun, four-pounder, depth charge thrower.

ordnance (noun)	cannon (noun)
military supplies	a shot in billiards in which the cue ball contacts one object ball and then the other
large but transportable armament	lower part of the leg extending from the hock to the fetlock in hoofed mammals
	a large artillery gun that is usually on wheels
	heavy automatic gun fired from an airplane
	(Middle Ages) a cylindrical piece of armor plate to protect the arm
	heavy gun fired from a tank

ordnance (verb)	cannon (verb)
	fire a cannon
	make a cannon