leptotenePronunciation: /ˈlɛptə(ʊ)tiːn/Definition of leptotene noun [mass noun] Biology the first stage of the prophase of meiosis, during which each chromosome becomes visible as two fine threads (chromatids). Origin: early 20th century: from lepto- 'narrow, fine' + Greek tainia 'band, ribbon'leptotene in other Oxford dictionaries Definition of leptotene in the US English dictionary
