gusset vs ring mail

gusset and ring mail both are nouns.

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

As nouns, ring mail is a hypernym of gusset; that is, ring mail is a word with a broader meaning than gusset:

Other hypernyms of gusset include chain armor, chain armour, chain mail, mail, ring armor, ring armour.

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