cloud

klaʊd

noun

a visible mass of condensed watery vapour floating in the atmosphere, typically high above the general level of the ground.

the sun had disappeared behind a cloud

verb

(of the sky) become overcast or gloomy.

the blue skies clouded over abruptly

become cloudy,cloud over,become overcast,become gloomy,grow dim,lour,blacken,darken,dim