ring armor vs chain mail

ring armor and chain mail both are nouns.

Word	Noun	Adjective	Verb	Adverb
ring armor	Yes	No	No	No
chain mail	Yes	No	No	No

As nouns, ring armor and chain mail are synonyms defined as:

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

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

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