Definitions

1. noun

A structure found in some female invertebrates, such as insects and arachnids, in which an egg is enveloped by a protective membrane or jacket.

“The entomologist carefully examined the oocyst to understand the reproductive cycle of the insect.”

2. noun

A type of egg sac found in some male invertebrates, such as certain species of spiders, in which sperm is stored.

“The oocyst of the male spider contained millions of sperm, ready to fertilize the female’s eggs.”