/ Dictionary / Index L leptotene: Meaning and Definition of Find definitions for: lep•to•tene Pronunciation: (lep'tu-tēn"), [key] — n. Cell Biol. a stage of cell division during the prophase of meiosis, in which the chromosomes are not distinct but appear as a mass of entangled threads. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: leptotene (Thesaurus) leptospirosis Lepus Related Content Daily Word Quiz: winsome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language