οὐκ ἔστι γῆρας τοῦδε τοῦ μιάσματος → that pollution never wears out, that pollution can never grow old
Ar. and P. ὀμίχλη, ἡ (Plato).
cloud: P. and V. νέφος, τό.
Met., darkness: P. and V. σκότος, ὁ or τό.