to cut open something, especially a dead body or a plant, and study its structure

In biology classes we used to dissect rats. 生物课上我们曾经过解剖老鼠。

to examine or consider something in detail

He's the kind of person who watches a movie and then dissects it for hours. 他是那种看完电影还要仔细分析上好几个小时的人。