The Collaborative International Dictionary of English v.0.48:
diplotene \diplotene\ n. (Cell biol.) the fourth stage of the prophase of meiosis, when the paired chromosomes being to separate. This stage follows the pachytene. [WordNet 1.5 +PJC]WordNet (r) 3.0 (2006):
diplotene n 1: the fourth stage of the prophase of meiosis