basin vs lavabo

basin and lavabo both are nouns.

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

As nouns, lavabo is a hyponym of basin; that is, lavabo is a word with a more specific, narrower meaning than basin:

basin (noun)	lavabo (noun)
a bowl-shaped vessel; usually used for holding food or liquids	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
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