armored combat vehicle vs army tank

armored combat vehicle and army tank both are nouns.

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

As nouns, armored combat vehicle and army tank are synonyms defined as:

armored combat vehicle and army tank: an enclosed armored military vehicle; has a cannon and moves on caterpillar treads

Other synonyms of armored combat vehicle include armoured combat vehicle, tank.

armored combat vehicle (noun)	army tank (noun)
an enclosed armored military vehicle; has a cannon and moves on caterpillar treads	an enclosed armored military vehicle; has a cannon and moves on caterpillar treads