washbowl vs handbasin

washbowl and handbasin both are nouns.

Word	Noun	Adjective	Verb	Adverb
washbowl	Yes	No	No	No
handbasin	Yes	No	No	No

As nouns, washbowl and handbasin are synonyms defined as:

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

washbowl (noun)	handbasin (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