pronucleus

[proh-noo-klee-uhs, -nyoo-]

noun

Cell Biology.

plural

pronuclei 

1. either of the gametic nuclei that unite in fertilization to form the nucleus of the zygote.

pronucleus

/ ˌprəʊˈnjuːklɪəs /

noun

1. the nucleus of a mature ovum or spermatozoan before fertilization

Word History and Origins

Origin of pronucleus¹

From New Latin, dating back to 1875–80; pro- ¹, nucleus