δύσοπτον

From LSJ

Sunt verba voces quibus hunc lenire dolorem possis, magnam morbi deponere partem → Words will avail the wretched mind to ease and much abate the dismal black disease.

Horace, Epistles 1.34

Russian (Dvoretsky)

δύσοπτον: τό мрачность, пасмурность (τῆς ἡμέρας Polyb.).