noun Botany, Mycology.
- a cell formed by fusion of two similar gametes, as in certain algae and fungi.
- a thick-walled sexual spore formed from the zygote of some fungi and algae
- A large, multinucleate spore formed by union of isogametes (gametes that are not distinguished by size and structure), as in certain algae or fungi. A zygospore develops thick, resistant walls and enters a period of dormancy before germinating.