zy·gote 
(zīgōt′)
(zīgōt′)n.
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.
zy·goti·cal·ly adv.