ἀρκάνη
From LSJ
ὅταν δὲ τἄμ' ἀθυμήσαντ' ἴδῃς, σύ μου τὸ δεινὸν καὶ διαφθαρὲν φρενῶν ἴσχναινε παραμυθοῦ θ' → whenever you see me despondent over my situation, do what you can to lessen and relieve what is wild and senseless in my thinking | whenever you see me despondent, you must cure the grim derangement of my mind and encourage me
Greek (Liddell-Scott)
ἀρκάνη: ἡ, «τὸ ῥάμμα, ᾧ τὸν στήμονα ἐγκαταπλέκουσιν αἱ διαζόμεναι» Ἡσύχ.· ἴδε Schneid Ind. Script. R. R. σ. 375 (πρβλ. ἄρκυς).