Meaning

noun the time of day immediately following sunset

verb become dusk

originFrom Middle English dosk, dusk(e) (“dusky”, adj.), from Old English dox (“dark, swarthy”), from Proto-Germanic *duskaz (“dark, smoky”), from Proto-Indo-European *dʰwes-, related to *dʰewh₂- (“smoke, mist, haze”). Cognate to Latin fuscus (“dark, dusky”), Sanskrit धूसर (dhūsara, “dust-colored”), Old Irish donn (“dark”). Related to dye, dust and dun (see these for more).

Etymology from Wiktionary, CC BY-SA 3.0