/ Dictionary / Index R rose moss: Meaning and Definition of Find definitions for: rose' moss" Pronunciation: [key] a portulaca, Portulaca grandiflora, widely cultivated for its showy flowers. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Rosemont Rosenberg Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language