Where does “etgras” come from?

etgras (Dutch) comes from Dutch gras, from Middle Dutch gras, from Old Dutch gras, from Proto-West Germanic gras, from Proto-Germanic grasą, from Proto-Indo-European ǵʰreh₁- — to become green, grow; to grow; to green, to grow.

etgras (Dutch): The lattermath, grass grown after the first crop...