/ Dictionary / Index M mudsill: Meaning and Definition of Find definitions for: mud•sill Pronunciation: (mud'sil"), [key] — n. the lowest sill of a structure, usually placed in or on the ground. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mud room mudskipper Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language