Where does “στείρωση” come from?

στείρωση (Greek) comes from Koine Greek στείρωσις, from Ancient Greek στεῖρος, from Proto-Hellenic steřřos, from Proto-Indo-European ster-yos, from Proto-Indo-European ster- — sterile, infertile.

στείρωση (Greek): neutering, spaying, act of making unable to procreate