clouding
['klaudiŋ]
n. 光泽面的暗晦, 湿润, 不清爽
例句与用法：
Dark clouds are a sign of rain or snow.
乌云是雨或雪将至的预兆。
On the night of December1,1930, a cloud of smog moved over a valley in Belgium, which caused thousands of people to become ill.
1930年12月1日晚上，一片烟雾飘过比利时的一个山谷，这使数千人病倒了。
详细释义：
n.
云状花纹