transferred. Of the clouds, sky, weather, etc.: Gloomy, dark, threatening. Sometimes figurative of attendant circumstances. Occasionally…

Of appearance, sound, atmosphere, etc.: menacing; awful; unsettling.

Of the sky, etc.: Dull, gloomy, threatening.

(of a situation, position, etc.) to appear unpromising or threatening; frequently with it.

figurative. Stormy, troublous, threatening. Chiefly U.S., esp. in the phrase to look squally.

figurative. Threatening an explosion of anger or passion; gloomy, frowning.

figurative. Suggestive of thunder; of threatening aspect, or charged with latent energy, like a thunder-cloud; violent, destructive, or terrifying…