ring mail vs brigandine

ring mail and brigandine both are nouns.

Word	Noun	Adjective	Verb	Adverb
ring mail	Yes	No	No	No
brigandine	Yes	No	No	No

As nouns, brigandine is a hyponym of ring mail; that is, brigandine is a word with a more specific, narrower meaning than ring mail:

ring mail: (Middle Ages) flexible armor made of interlinked metal rings
brigandine: a medieval coat of chain mail consisting of metal rings sewn onto leather or cloth

Other hyponyms of ring mail include habergeon, byrnie, hauberk, gusset, voider.

ring mail (noun)	brigandine (noun)
(Middle Ages) flexible armor made of interlinked metal rings	a medieval coat of chain mail consisting of metal rings sewn onto leather or cloth