Definitions

1. noun

A type of spore that results from the fusion of two gametangia in certain algae, such as ferns and liverworts, and is often found in the form of a dormant, usually single, cell.

“The botanist studied the formation of oospores in the fern species.”

2. noun

In fungi, a type of spore that is similar to an ascospore but is usually larger and more resistant to environmental stress.

“The mycologist examined the properties of oospores produced by the fungus.”