\Sump\, n. [Cf. G. sumpf a sump in a mine, a swamp, akin to
LG. sump, D. somp a swamp, Dan. & Sw. sump, and perhaps to E.
swamp.]
1. (Metal.) A round pit of stone, lined with clay, for
   receiving the metal on its first fusion. --Ray.
2. The cistern or reservoir made at the lowest point of a
   mine, from which is pumped the water which accumulates
   there.
3. A pond of water for salt works. --Knight.
4. A puddle or dirty pool. [Prov. Eng.]
{Sump fuse}, a fuse used in blasting under water.
{Sump men} (Mining), the men who sink the sump in a mine.