lavabo(n = noun.artifact) handbasin, wash-hand basin, washbasin, washbowl - a basin for washing the hands (`wash-hand basin' is a British expression);
is a kind of basin
is a part of bath, bathroom

lavabo, n. (pl. -os)
1 RC Ch. a the ritual washing of the celebrant's hands at the offertory of the Mass. b a towel or basin used for this.
2 a monastery washing-trough.
3 a wash-basin.

Etymology:
L, = I will wash, first word of Psalm 26:6