ἁλωνοτριβέω
From LSJ
Ἕκτορ νῦν σὺ μὲν ὧδε θέεις ἀκίχητα διώκων → Hector, you run in pursuit of something unattainable | Hector, now art thou hasting thus vainly after what thou mayest not attain | Hector, now you are hasting thus vainly after what you may not attain
English (LSJ)
A = ἁλωνεύομαι, Suid. S.V. ἁλωνία. II beat on a threshing-floor, Longus 3.29.