• 曇くもる — to become cloudy; to cloud over
• 曇天どんてん — overcast sky
• 曇くもり空 — cloudy sky
• 薄曇うすぐもり — thin cloud; light overcast
• 曇くもり止どめ — anti-fog coating (glasses, lenses)

In 曇, the sun radical 日 sits beneath clouds (雲). The image is literal: sunlight veiled by cloud cover — hence “cloudy” or “gloomy.” When the sun is hidden, brightness fades and the mood grows muted.

Think of 曇天（どんてん）— that heavy, overcast ceiling of clouds. When the 日 (sun) can’t break through the 雲 (clouds), the world looks and feels subdued. That’s the natural sense carried by 曇.