δια-κενῆς
or better διὰ κενῆς (i.e. πράξεως), adverb in vain, idly, to no purpose, [[ 5th c.BC: Hippocrates Medicus “ἐπιδημίαι” 7.5, 5th c.BC: Euripides Tragicus “Troades” 758, 5th c.BC: Thucydides Historicus 4.126; δ. ἄλλως 5th-6th c.BC: Aristophanes Comicus “Vespae” 929; μάτην δ. 5th-6th c.BC: Plato Comicus 174.21. ] Refs 5th c.BC+]