lavabo vs washbasin

lavabo and washbasin both are nouns.

Word	Noun	Adjective	Verb	Adverb
lavabo	Yes	No	No	No
washbasin	Yes	No	No	No

As nouns, lavabo and washbasin are synonyms defined as:

Other synonyms of lavabo include handbasin, wash-hand basin, washbowl.

lavabo (noun)	washbasin (noun)
a basin for washing the hands	a basin for washing the hands
	a bathroom sink that is permanently installed and connected to a water supply and drainpipe; where you can wash your hands and face