Sink n.
  1. A drain to carry off filthy water; a jakes.
  2. A shallow box or vessel of wood, stone, iron, or other material, connected with a drain, and used for receiving filthy water, etc., as in a kitchen.
  3. A hole or low place in land or rock, where waters sink and are lost; -- called also sink hole. [U. S.]
  4. The lowest part of a natural hollow or closed basin whence the water of one or more streams escapes by evaporation; as, the sink of the Humboldt River. [Western U. S.]
  Sink hole. (a) The opening to a sink drain. (b) A cesspool. (c) Same as Sink, n., 3.
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