master bedroom vs bedchamber

master bedroom and bedchamber both are nouns.

Word	Noun	Adjective	Verb	Adverb
master bedroom	Yes	No	No	No
bedchamber	Yes	No	No	No

As nouns, bedchamber is a hypernym of master bedroom; that is, bedchamber is a word with a broader meaning than master bedroom:

master bedroom: the principal bedroom in a house; usually occupied by the head of the household
bedchamber: a room used primarily for sleeping

Other hypernyms of master bedroom include bedroom, chamber, sleeping accommodation, sleeping room.

master bedroom (noun)	bedchamber (noun)
the principal bedroom in a house; usually occupied by the head of the household	a room used primarily for sleeping