• 雲くも — cloud
• 雨あま雲ぐも — rain cloud
• 黒雲くろくも — dark cloud
• 白はく雲うん — white cloud
• 雲海うんかい — sea of clouds
• 星雲せいうん — nebula / galaxy

More examples ▼

• 入道にゅうどう雲ぐも — cumulonimbus cloud
• 雲くも行ゆき — weather outlook / turn of events
• 雷雲らいうん — thundercloud
• 暗雲あんうん — dark clouds (often metaphorical: signs of trouble)

雲 combines 雨 (rain) and 云 (used mainly for sound), giving the idea of a mass of moisture in the sky.

It’s common in weather words, and it also appears in poetic expressions about change, uncertainty, and atmosphere.