Definitions of basin:

• noun:   a bowl-shaped vessel; usually used for holding food or liquids

  Example: "She mixed the dough in a large basin"

• noun:   a natural depression in the surface of the land often with a lake at the bottom of it

  Example: "The basin of the Great Salt Lake"

• noun:   the quantity that a basin will hold

  Example: "A basinful of water"

• noun:   a bathroom or lavatory sink that is permanently installed and connected to a water supply and drainpipe; where you wash your hands and face

  Example: "He ran some water in the basin and splashed it on his face"

• noun:   the entire geographical area drained by a river and its tributaries

  Example: "Flood control in the Missouri basin"