water closet vs closet

water closet and closet both are nouns.

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

As nouns, water closet and closet are synonyms defined as:

Other synonyms of water closet include loo, W.C..

water closet (noun)	closet (noun)
a toilet in Britain	a small private room for study or prayer
	a toilet in Britain
	a tall piece of furniture that provides storage space for clothes; has a door and rails or hooks for hanging clothes
	a small room (or recess) or cabinet used for storage space

water closet (verb)	closet (verb)
	confine to a small space, as for intensive work