/ˌpɝː ˈseɪ/
used meaning ‘by itself’ to show that you are referring to sth on its own, rather than in connection with other things 本身；本质上
The drug is not harmful per se, but is dangerous when taken with alcohol.
这种药本身无害，但与酒同服就危险了。
The color of the shell per se does not affect the quality of the egg.