/ Dictionary / Index B blue mud: Meaning and Definition of Find definitions for: blue' mud' Pronunciation: [key] — Geol., Geol.,Oceanog. a deep-sea sediment of fine silt and clay that derives its bluish color from organic material and iron sulfide. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Blue Mountains blue myrtle Related Content Daily Word Quiz: hale Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language