Where does “βάρος” come from?

βάρος (Greek) comes from Ancient Greek βάρος, from Ancient Greek βαρύς, from Proto-Hellenic gʷarus, from Proto-Indo-European gʷréh₂us, from Proto-Indo-European -us — Forms adjectives from Caland system roots.

βάρος (Greek): mass; weight, heaviness; burden, load, cargo