What the Italian name for first son?

There isn't a single, specific Italian name for a "first son". It's more about the order of birth than a distinct title.

However, some terms can be used:

* Primogenito: This is the most direct translation of "firstborn," which could apply to either a son or a daughter.

* Figlio primogenito: This is more specific, literally meaning "firstborn son."

* Fratello maggiore: This means "older brother", but could also be used to describe the firstborn son if he has younger siblings.

Ultimately, the best way to refer to a first son in Italian would be to simply say "il figlio maggiore" (the eldest son) or "il primo figlio maschio" (the first male child).