/ Dictionary / Index L lepto: Meaning and Definition of Find definitions for: lep•to Pronunciation: (lep'tō), [key] — n. Informal. leptospirosis. lepto- Pronunciation: [key] a combining form meaning “thin,” “fine,” “slight,” used in the formation of compound words: leptophyllous. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. -lepsy leptocephalus Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language