major-domo vs retainer

major-domo and retainer both are nouns.

Word	Noun	Adjective	Verb	Adverb
major-domo	Yes	No	No	No
retainer	Yes	No	No	No

As nouns, retainer is a hypernym of major-domo; that is, retainer is a word with a broader meaning than major-domo:

major-domo: the chief steward or butler of a great household
retainer: a person working in the service of another (especially in the household)

Other hypernyms of major-domo include servant.

major-domo (noun)	retainer (noun)
the chief steward or butler of a great household	a dental appliance that holds teeth (or a prosthesis) in position after orthodontic treatment
	a person working in the service of another (especially in the household)
	a fee charged in advance to retain the services of someone