Where does “χάμω” come from?

χάμω (Greek) comes from Byzantine Greek χάμω, from Ancient Greek χαμαί, from Ancient Greek Χθών, from Proto-Indo-European dʰéǵʰōm, from Proto-Indo-European -ōm, from Proto-Indo-European -mi.

χάμω (Greek): down, on the ground, on the floor