Where does “Σποράδες” come from?

Σποράδες (Ancient Greek) comes from Ancient Greek σποράς, from Ancient Greek σπορά, from Ancient Greek σπείρω, from Proto-Hellenic spéřřō, from Proto-Indo-European spéryeti, from Proto-Indo-European sper- — to fidget, twitch; to push; to be quick; to...