washbasin vs basin

washbasin and basin both are nouns.

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

As nouns, basin is a hypernym of washbasin; that is, basin is a word with a broader meaning than washbasin:

As nouns, washbasin and basin are synonyms defined as:

washbasin and basin: a bathroom sink that is permanently installed and connected to a water supply and drainpipe; where you can wash your hands and face

Other synonyms of washbasin include lavatory, washbowl, washstand.

washbasin (noun)	basin (noun)
a basin for washing the hands	a bowl-shaped vessel; usually used for holding food or liquids
a bathroom sink that is permanently installed and connected to a water supply and drainpipe; where you can wash your hands and face	a bathroom sink that is permanently installed and connected to a water supply and drainpipe; where you can wash your hands and face
	the entire geographical area drained by a river and its tributaries; an area characterized by all runoff being conveyed to the same outlet
	a natural depression in the surface of the land often with a lake at the bottom of it
	the quantity that a basin will hold