hauberk vs chain armour

hauberk and chain armour both are nouns.

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

As nouns, chain armour is a hypernym of hauberk; that is, chain armour is a word with a broader meaning than hauberk:

hauberk: a long (usually sleeveless) tunic of chain mail formerly worn as defensive armor
chain armour: (Middle Ages) flexible armor made of interlinked metal rings

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

hauberk (noun)	chain armour (noun)
a long (usually sleeveless) tunic of chain mail formerly worn as defensive armor	(Middle Ages) flexible armor made of interlinked metal rings