“birth”

To release live offspring from the body into the environment.

The amount of time that some being has been alive, or that some thing has been in existence, as measured from its birth or origin until the present or until some other given reference point. (Often measured in number of years; alternatively in months, days, hours, etc.; see also the usage notes)

A person who has not yet reached adulthood, whether natural (puberty), cultural (initiation), or legal (majority).

A very young human, particularly from birth to a couple of years old or until walking is fully mastered.