ἐξῆν

From LSJ

οὔποτε ποιήσεις τὸν καρκίνον ὀρθὰ βαδίζειν → thou shalt never make the crab walk straight

Source

French (Bailly abrégé)

impf. de ἔξεστι, v. ἔξειμι¹.

Russian (Dvoretsky)

ἐξῆν: 3 л. sing. impf. к ἔξειμι I.