[ C ] usually disapproving a large, angry crowd, especially one that could easily become violent暴民，乱民

[ C ] informal a group of people who are friends or who are similar in some way一群人，一伙；帮派，团伙

[ S ] informal an organization of criminals犯罪集团

[ T usually passive ] to come together around someone in a crowd to express admiration, interest, or anger（人群）围住，围聚

[ I or T ] When birds or small animals mob a bigger or more frightening bird or animal that is hunting them, they attack it together and force it to go away.（鸟群或一群小动物）成群袭击，围攻（猛禽或猛兽）