ἐν καιρῷ
From LSJ
Οὕτως ἔδειξέν μοι κύριος καὶ ἰδοὺ ἐπιγονὴ ἀκρίδων ἐρχομένη ἑωθινή, καὶ ἰδοὺ βροῦχος εἷς Γωγ ὁ βασιλεύς (Amos 7:1) → Thus the Lord showed me and look, early-morning offspring of locusts coming, and look, one locust-larva: Gog the king.
Greek > English (Woodhouse)
early, at the right moment, at the right time, in the nick of time