cloudy的意思是:多云的；被云遮住的；阴云密布的；阴天的；不清澈的；不透明的；浑浊的！所以它用作形容天气时，是多云天气。例如:

Tonight will be cloudy.今天夜间多云。The day was dull, with a cloudy sky.天气阴暗多云。The needle on the barometer was pointing to "cloudy".晴雨表的指针指向“多云”。