ring mail vs gusset

ring mail and gusset both are nouns.

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

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

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

ring mail (noun)	gusset (noun)
(Middle Ages) flexible armor made of interlinked metal rings	a piece of material used to strengthen or enlarge a garment
	a metal plate used to strengthen a joist
	a piece of chain mail covering a place unprotected by armor plate