handbasin vs wash-hand basin

handbasin and wash-hand basin both are nouns.

Word	Noun	Adjective	Verb	Adverb
handbasin	Yes	No	No	No
wash-hand basin	Yes	No	No	No

As nouns, handbasin and wash-hand basin are synonyms defined as:

Other synonyms of handbasin include lavabo, washbasin, washbowl.

handbasin (noun)	wash-hand basin (noun)
a basin for washing the hands	a basin for washing the hands