μὴ δὶς πρὸς τὸν αὐτὸν λίθον πταίειν → do not stumble twice on the same stone
κενῶς: ἴδε ἐν λ. κενὸς Ι. 2.
adv.à vide.Étymologie: κενός.
adverb from κενός; vainly, i.e. to no purpose: in vain.
