Skip to definition.
Get the FREE one-click dictionary software for Windows or the iPhone/iPad and Android apps


Noun: zona pellucida  'zow-nu pu'loo-si-du
  1. Thick membrane around the mammalian ovum; can be penetrated by one sperm in the fertilization process; usually remains around the fertilized egg until it is implanted in the wall of the uterus

Type of: zona, zone

Encyclopedia: Zona pellucida