lavatory vs bathroom

lavatory and bathroom both are nouns.

Word	Noun	Adjective	Verb	Adverb
lavatory	Yes	No	No	No
bathroom	Yes	No	No	No

As nouns, lavatory and bathroom are synonyms defined as:

lavatory and bathroom: a room or building equipped with one or more toilets

Other synonyms of lavatory include can, john, lav, privy, toilet.

lavatory (noun)	bathroom (noun)
a room or building equipped with one or more toilets	a room (as in a residence) containing a bathtub or shower and usually a washbasin and toilet
a bathroom sink that is permanently installed and connected to a water supply and drainpipe; where you can wash your hands and face	a room or building equipped with one or more toilets
a toilet that is cleaned of waste by the flow of water through it