sump definition by Webster's New World
- a pit, cistern, cesspool, etc. for draining, collecting, or storing liquids
- Brit. oil pan
- a pit or pool at the bottom of a shaft or mine, in which water collects and from which it is pumped
- an excavation at the head of a tunnel or shaft
Origin: Middle English sompe, swamp
sump definition by American Heritage Dictionary
- a. A low-lying place, such as a pit, that receives drainage.b. A cesspool.
- A hole at the lowest point of a mine shaft into which water is drained in order to be pumped out.
- The crankcase or oil reservoir of an internal-combustion engine.
Origin: Middle English sompe, marsh, from Middle Low German sump or from Middle Dutch somp. Sense 2, from German Sumpf, swamp, sump, from Middle High German, swamp.