εἰδῶ

From LSJ

αἱ μέν ἀποφάσεις ἐπί τῶν θείων ἀληθεῖς, αἱ δέ καταφάσεις ἀνάρμοστοι τῇ κρυφιότητι τῶν ἀποῤῥήτων → as concerns the things of the gods, negative pronouncements are true, but positive ones are inadequate to their hidden character

Source

French (Bailly abrégé)

ῇς, ῇ;
sbj. de οἶδα, pf.2 de *εἴδω.

Russian (Dvoretsky)

εἰδῶ: эп. εἰδέω pf. conjct. к *εἴδω.