adverb · done in a random, arbitrary, or careless manner

在公共场所不要乱扔垃圾。

adjective, verb · in a state of physical confusion, messiness, or mental distraction

我的房间太乱了，需要整理一下。

noun, adjective, verb · social or political disorder, riot, or period of chaos

战争之后，那个国家陷入了大乱。

adjective · involving improper or illicit sexual relations

这两个人的关系非常乱。

verb · to throw into disorder or disturb the existing order of things

你把书架上的书籍顺序弄乱了。