a. A low-lying place, such as a pit, that receives drainage.
b. A cesspool.
2. A hole at the lowest point of a mine shaft into which water is drained in order to be pumped out.
3. The crankcase or oil reservoir of an internal-combustion engine.
[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.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.