capacitation

of sperm
https://doi.org/10.1351/goldbook.10486

Sum of biochemical changes undergone by mammalian spermatozoa in the female genital tract that enables them to penetrate and fertilize (see fertilization) an egg.

Source:
PAC, 2016, 88, 713. (Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)) on page 732 [Terms] [Paper]