πτερύγεσσιν

From LSJ

κατὰ τὸν δεύτερον, φασί, πλοῦν τὰ ἐλάχιστα ληπτέον τῶν κακῶν → we must as second best, as people say, take the least of the evils

Source

French (Bailly abrégé)

dat. pl. poét. de πτέρυξ.