canister shot vs ammunition

canister shot and ammunition both are nouns.

Word	Noun	Adjective	Verb	Adverb
canister shot	Yes	No	No	No
ammunition	Yes	No	No	No

As nouns, ammunition is a hypernym of canister shot; that is, ammunition is a word with a broader meaning than canister shot:

canister shot: a metallic cylinder packed with shot and used as ammunition in a firearm
ammunition: projectiles to be fired from a gun

Other hypernyms of canister shot include ammo.

canister shot (noun)	ammunition (noun)
a metallic cylinder packed with shot and used as ammunition in a firearm	projectiles to be fired from a gun
	information that can be used to attack or defend a claim or argument or viewpoint
	any nuclear or chemical or biological material that can be used as a weapon of mass destruction