He took many pre-med classes in college to prepare for medical school.

pre-med 是 premedical 的缩写形式，由前缀 pre-（表示"在...之前"）和 medical（医学的）组成，字面意思是"医学前的"。 pre-med classes 指为进入医学院做准备的基础课程，即"医学预科课程"。