W.C. vs bathroom

W.C. and bathroom both are nouns.

Word	Noun	Adjective	Verb	Adverb
W.C.	Yes	No	No	No
bathroom	Yes	No	No	No

As nouns, bathroom is a hypernym of W.C.; that is, bathroom is a word with a broader meaning than W.C.:

Other hypernyms of W.C. include can, john, lav, lavatory, privy, toilet.

W.C. (noun)	bathroom (noun)
a toilet in Britain	a room (as in a residence) containing a bathtub or shower and usually a washbasin and toilet
	a room or building equipped with one or more toilets