• 雲くも — cloud
• 雨あま雲ぐも — rain cloud
• 雲海うんかい — sea of clouds
• 白はく雲うん — white cloud
• 雲くも行ゆき — weather outlook
• 入道にゅうどう雲ぐも — cumulonimbus cloud

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.