/ Dictionary / Index T Tycho: Meaning and Definition of Find definitions for: Ty•cho Pronunciation: (tī'kō), [key] — n. a prominent crater in the third quadrant of the face of the moon, about 56 miles (90 km) in diameter. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Tyche Tychonic system Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language