army tank vs panzer

army tank and panzer both are nouns.

Word	Noun	Adjective	Verb	Adverb
army tank	Yes	No	No	No
panzer	Yes	No	No	No

As nouns, panzer is a hyponym of army tank; that is, panzer is a word with a more specific, narrower meaning than army tank:

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

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