неосторожно

From LSJ

ποταμῷ γὰρ οὐκ ἔστιν ἐμβῆναι δὶς τῷ αὐτῷ → it is impossible to step twice in the same river, you cannot step twice into the same rivers

Source

Russian > Greek

ἀπαρατηρήτως, ἀφυλάκτως