chain armour vs ring armour

chain armour and ring armour both are nouns.

Word	Noun	Adjective	Verb	Adverb
chain armour	Yes	No	No	No
ring armour	Yes	No	No	No

As nouns, chain armour and ring armour are synonyms defined as:

chain armour and ring armour: (Middle Ages) flexible armor made of interlinked metal rings

Other synonyms of chain armour include chain armor, chain mail, mail, ring armor, ring mail.

chain armour (noun)	ring armour (noun)
(Middle Ages) flexible armor made of interlinked metal rings	(Middle Ages) flexible armor made of interlinked metal rings