ὀπισθοφυλακεῖν

From LSJ

αὔριον ὔμμε‎ πάσας ἐγὼ λουσῶ Συβαρίτιδος ἔνδοθι λίμνας‎ → tomorrow I'll wash you one and all in Sybaris lake

Source

Greek > English (Woodhouse Verbs Reversed)

(see also ὀπισθοφυλακέω): be the rear-guard