It was cloudy yesterday.

　　昨天是陰天。

　　Men are subject to sudden changes of fortune as the moon is subject to the changes of being full and crescent, cloudy and clear.

　　人有旦夕禍福，月有陰晴圓缺。

　　The sky is cloudy, and looks like rain.

　　天空陰沉沉的，像是要下雨。

　　The room became cloudy with a blue haze of smoke.

　　藍(lán)幽幽的煙使房間霧氣騰騰。

　　This is a cup of cloudy water.

　　這是一杯混濁的水。