water closet vs toilet

water closet and toilet both are nouns.

Word	Noun	Adjective	Verb	Adverb
water closet	Yes	No	No	No
toilet	Yes	No	No	No

As nouns, toilet is a hypernym of water closet; that is, toilet is a word with a broader meaning than water closet:

Other hypernyms of water closet include bathroom, can, john, lav, lavatory, privy.

water closet (noun)	toilet (noun)
a toilet in Britain	the act of dressing and preparing yourself
	a room or building equipped with one or more toilets
	a plumbing fixture for defecation and urination
	misfortune resulting in lost effort or money