/ Dictionary / Index R Rümker: Meaning and Definition of Find definitions for: Rüm•ker Pronunciation: (rum'kur), [key] — n. a crater in the second quadrant of the face of the moon: about 25 miles (40 km) in diameter. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ruminate Ruml Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language