Oocyte: A female germ cell in the process of development. The oocyte is produced in the ovary by an ancestral cell called an oogonium and gives rise to the ovum (the egg), which can be fertilized. From Healthy Resources Common Causes of InfertilityWhich Infertility Treatment is for You? Featured Centers What Are the Best PsA Treatments for You?Understanding Biologics 10 Things People With Depression Wish You Knew Health Solutions From Our Sponsors