army tank vs armored vehicle

army tank and armored vehicle both are nouns.

Word	Noun	Adjective	Verb	Adverb
army tank	Yes	No	No	No
armored vehicle	Yes	No	No	No

As nouns, armored vehicle is a hypernym of army tank; that is, armored vehicle is a word with a broader meaning than army tank:

army tank: an enclosed armored military vehicle; has a cannon and moves on caterpillar treads
armored vehicle: a vehicle that is protected by armor plate

Other hypernyms of army tank include armoured vehicle, military vehicle, tracked vehicle.

army tank (noun)	armored vehicle (noun)
an enclosed armored military vehicle; has a cannon and moves on caterpillar treads	a vehicle that is protected by armor plate