overcast
adj.describing a sky that is completely covered with clouds, making it look grey and dull. You use this when there is no blue sky visible and the sun is hidden.
adj.covered with clouds; dull and grey. Often used predicatively after 'be' or 'become', or attributively to describe weather conditions.
“The sky is overcast and it looks like rain.”
“We decided to cancel the picnic because the morning was cold and overcast.”
“Despite the overcast conditions, the photographer managed to capture the architectural details of the cathedral without the harsh shadows caused by direct sunlight.”
Commonly used to describe the sky or the weather; often follows the verb 'to be'.
From Middle English overcasten, equivalent to over- + cast. Compare Swedish överkast.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.