/ Dictionary / Index S Seleucus: Meaning and Definition of Find definitions for: Se•leu•cus Pronunciation: (si-l'kus), [key] — n. a crater in the second quadrant of the face of the moon: about 32 miles (51.2 km) in diameter. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: seleucus (Thesaurus) Seleucidan Seleucus I Related Content Daily Word Quiz: eccentric Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language