IPA: //ˈpoʊstˌɡrædʒuɪt//
KK: /ˈpoʊstˌgrædʒuɪt/
Relating to studies or education that occur after completing a bachelor's degree, usually at a university.
She decided to pursue postgraduate studies in psychology to deepen her knowledge.
A person who is studying after completing their first degree, usually at a university, to gain more advanced knowledge or qualifications.
She decided to become a postgraduate student to pursue her master's degree in psychology.
Postgraduate → It is formed from "post-" (meaning after) and "graduate" (from Latin "graduatus", meaning one who has taken a degree). The word "postgraduate" refers to studies or work undertaken after obtaining a degree.
Think of 'after' ('post-') completing a degree ('graduate') — that's what postgraduate means.