sump

 
Pronunciation: /sʌmp/

noun

  • 1a hollow or depression in which liquid collects, especially one in the floor of a mine or cave.
  • a cesspool.
  • 2the base of an internal-combustion engine, which serves as a reservoir of oil for the lubrication system.

Origin:

Middle English (in the sense 'marsh'): from Middle Dutch or Low German sump, or (in the mining sense) from German Sumpf; related to swamp