cloudbank
From Longman Dictionary of Contemporary EnglishRelated topics: Meteorologycloudbankcloud‧bank /ˈklaʊdbæŋk/ noun [countable] British English HEMa thick mass of low cloudExamples from the Corpuscloudbank• A low, scudding cloudbank was coming off the western horizon, purple with unshed rain.• The cloudbank spread, seeming to soak up the light.• Lightning struck out of the towering cloudbank.