adverb · roughly, about, or estimated

参加这次户外活动的约有一百人。

verb · to make an appointment or invite someone to do something

我约了朋友一起去看电影。

noun, verb · an agreement, treaty, or formal arrangement

双方签署了一项长期贸易条约。

verb · to weigh in a balance or on a scale

把这块肉约一约。

verb · brief, succinct, or simple in style

他的发言辞约而意丰。

adverb · to simplify a mathematical fraction to its lower terms

这个分数可以约简为三分之一。

verb, adjective · to restrain, limit, or practice economy

他在开支方面一向非常俭约。