verb · points of commonality, overlap, or social connection and interaction between people or things

他们两人的生活圈子完全没有交集。

verb · the set containing all elements common to two or more sets in mathematical set theory

这两个集合的交集为空集。

idiom · to occur simultaneously or intermingle, especially regarding diverse or conflicting emotions

想到往事，他内心百感交集。