godan verb (-su), transitive verb
bear a child; give birth to
Formal or literary transitive verb. In modern everyday Japanese, 産む (うむ) is more common for giving birth.
彼女は元気な男の子を生した。
She gave birth to a healthy baby boy.
The standard modern verb for 'give birth'. 生す is a formal/literary alternative with the same meaning.
The kanji 生 carries the core meaning of 'life' or 'birth'. The reading なす is a native Japanese verb, but its exact historical derivation is uncertain.