Definition of zona pellucida in English:

zona pellucida

nounplural noun zonae pellucidae/ˈzōˌnē pəˈlo͞osəˌdē/ /ˈzōˌnī pəˈlo͞osəˌdī/

Anatomy Zoology
  • The thick transparent membrane surrounding a mammalian ovum before implantation.

    ‘At this stage the embryo releases itself from the zona pellucida still surrounding it, and implants into the uterine wall.’
    • ‘The embryo must hatch out of the zona pellucida prior to implantation into the uterine wall.’
    • ‘The secondary oocyte and the polar body remain surrounded by the zona pellucida and the cumulus oophorus.’
    • ‘The scientists drilled through the egg's protective layer, the zona pellucida, removed a plug, and then extracted the DNA and polar body through the hole.’
    • ‘The onset of hyperactive movement occurs near the site of fertilization and is crucial for penetrating the egg's zona pellucida.’


zona pellucida

/ˌzōnə pəˈlo͞osədə/ /ˌzoʊnə pəˈlusədə/


Mid 19th century from Latin, literally ‘pellucid girdle’.