1.  washbowl(n = noun.artifact) basin, lavatory, washbasin, washstand - a bathroom sink that is permanently installed and connected to a water supply and drainpipe; where you can wash your hands and face; "he ran some water in the basin and splashed it on his face"
is a kind of sink

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

   A basin, or bowl, to hold water for washing one's hands, face, etc. [1913 Webster]