Meaning

noun an atmosphere in which visibility is reduced because of a cloud of some substance

verb make dark, dim, or gloomy

originFrom Middle English merke, mirke, from Old English mirce, myrce (“dark, gloomy, evil”) and Old Norse myrkr (“dark, murky”), both from Proto-Germanic *merkuz (“dark”), from Proto-Indo-European *mergʷ- (“to flicker; to darken; to be dark”). Cognate Danish mørk (“dark”), Norwegian mørk (“dark”), Swedish mörk (“dark”), Icelandic myrkur (“dark”), as also Albanian murg (“dark”), Proto-Slavic *morkъ…

Etymology from Wiktionary, CC BY-SA 3.0