1. Semisolid material such as the type precipitated by sewage treatment.
2. Mud, mire, or ooze covering the ground or forming a deposit, as on a riverbed.
3. Finely broken or half-formed ice on a body of water, especially the sea.
4. A semisolid mass composed of an aggregation of cells (such as red blood cells in blood vessels) or particulate matter (such as cholesterol crystals and calcium salts in bile).
intr.v. sludged, sludg·ing, sludg·es
To form sludge.
[Perhaps alteration of dialectal slutch, mire.]
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.