Where does “Εἰρηναῖος” come from?

Εἰρηναῖος (Ancient Greek) comes from Ancient Greek εἰρηναῖος, from Ancient Greek Εἰρήνη, from Ancient Greek εἰρήνη, from Ancient Greek εἴρω, from Proto-Hellenic wéřřō, from Proto-Indo-European wéryeti, from Proto-Indo-European werh₁- — to speak, say.

Εἰρηναῖος (Ancient Greek): peaceful, peaceable