1. The cell formed by the union of two gametes, especially a fertilized ovum before cleavage.
2. The organism that develops from a zygote.
[From Greek zugōtos, yoked, from zugoun, to yoke; see yeug- in the Appendix of Indo-European roots.]
zy·gotic (-gŏtĭk) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.