cannon vs heavy weapon

cannon and heavy weapon both are nouns.

Word	Noun	Adjective	Verb	Adverb
cannon	Yes	No	Yes	No
heavy weapon	Yes	No	No	No

As nouns, heavy weapon is a hypernym of cannon; that is, heavy weapon is a word with a broader meaning than cannon:

Other hypernyms of cannon include artillery, gun, ordnance.

cannon (noun)	heavy weapon (noun)
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

cannon (verb)	heavy weapon (verb)
fire a cannon
make a cannon