/ Dictionary / Index R rimstone: Meaning and Definition of Find definitions for: rim•stone Pronunciation: (rim'stōn"), [key] — n. Geol. a calcareous deposit forming a dam at the edge or outlet of an overflowing pool of water, as in a cavern. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Rimsky-Korsakov rimy Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language