drifting clouds
Literary or poetic term for clouds moving across the sky. Often used in set phrases like 行雲流水 (こううんりゅうすい) to describe a natural, unforced flow.
Drifting clouds were moving across the sky.
彼の文章は行雲流水のごとく自然だ。
His writing flows as naturally as drifting clouds and flowing water.
Compound of 行 (going, moving) and 雲 (cloud). The reading is on'yomi (こううん).