Meaning

noun the time of day immediately following sunset

originFrom Middle English gloming, from Old English glōmung, from Old English glōm (“twilight”). Related to glow. The OED notes: "The vowel of the modern gloaming is anomalous, as Old English glōmung should normally become glooming. The explanation is probably that the ō was shortened in the compound ǣfen-glommung (as the spelling seems to show was actually the case), and that from this compound there…

Etymology from Wiktionary, CC BY-SA 3.0