birth

https://doi.org/10.1351/goldbook.10458
Start of life as a physically separate being, e.g., the emergence of a baby from the body of its mother, or the hatching of an egg.
Source:
PAC, 2016, 88, 713. (Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)) on page 730 [Terms] [Paper]