乌, a pictographic character of a crow, serves as a phonetic component to form characters. Don’t forget to compare 乌 and 鸟.
From the pictograms of the two characters, we can see 乌 is a bird without eyes, which is also demonstrated by its writing 乌 (without that point which stands for the eye of a bird 鸟? )
乌 serves as a phonetic component to form characters
呜、邬、 钨 with the same pronunciation wū
坞 wù
Apparently, 乌 is not so productive as 鸟.
Common words and set phrases of 乌
乌有 乌羊 乌龙 乌龟 金乌 乌鸟 乌获 乌桕 乌鹊 乌鸦 化为乌有 爱屋及乌 乌托邦 乌鸟私情 子虚乌有 乌衣巷 乌合之众 乌夜啼 青乌术 乌烟瘴气