Sump

1. n. A puddle or dirty pool.
2. n. A round pit of stone, lined with clay, for receiving the metal on its first fusion.
3. n. The cistern or reservoir made at the lowest point of a mine, from which is pumped the water which accumulates there.
4. n. A pond of water for salt works.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.