Etymology
The adjective is borrowed from Scots dreich (“hard to bear, dreary, tedious, wearisome; interminable, long-winded; dull, uninteresting; slow, tardy; doleful, gloomy; baffling, difficult; difficult to reach, inaccessible”), from Middle English dregh, dri, drie (“burdensome; depressing, dismal; large, tall; lasting, long; long-suffering, patient; tedious; of blows: hard, heavy; of the face: unchanging, unmoved; of a person: strong, valorous”) [and other forms], from Old English *drēog, drēoh (“earnest; fit; sober”), and then probably partly:
* shortened from Old English ġedrēog (“calm, quiet; sober; fit, suitable”, adjective), from ġe- (prefix forming adjectives of association or similarity) + Proto-Germanic *dreugaz (“enduring, lasting”) (from *dreuganą (“to serve, be a retainer”), from Pro