chain armour vs suit of armour

chain armour and suit of armour both are nouns.

Word	Noun	Adjective	Verb	Adverb
chain armour	Yes	No	No	No
suit of armour	Yes	No	No	No

As nouns, suit of armour is a hypernym of chain armour; that is, suit of armour is a word with a broader meaning than chain armour:

Other hypernyms of chain armour include body armor, body armour, cataphract, coat of mail, suit of armor.

chain armour (noun)	suit of armour (noun)
(Middle Ages) flexible armor made of interlinked metal rings	armor that protects the wearer's whole body