1(of sth long) wide; thick
2(of sth granular) coarse
3(of a voice) gruff
4(of sb's manner etc) rough; crude; careless; rude
Examples
nà那gè个xiǎo jie小姐gāng cái刚才shuō说cū粗huà话a啊？
那个小姐刚才说粗话啊？
Did that lady just swear?
我加粗了我觉得有趣的文章。
I've boldfaced the articles that I found interesting.
你不能在电视上骂粗口。
You can't say four-letter words on TV.