/ Dictionary / Index R rubstone: Meaning and Definition of Find definitions for: rub•stone Pronunciation: (rub'stōn"), [key] — n. a stone, esp. a whetstone, used for polishing or sharpening. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. rubrum lily Rubtsovsk Related Content Daily Word Quiz: portent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language