/ Dictionary / Index M Mills grenade: Meaning and Definition of Find definitions for: Mills' grenade" Pronunciation: [key] a type of high-explosive grenade weighing about 1.5 lb. (0.7 kg). Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Mills cross millstone Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language