Meaning of “postgraduate” - Learner’s Dictionary

postgraduate

noun [ C ] uk us /ˌpəʊstˈɡrædʒuət/ (informal postgrad)

UK (US graduate student) a student who has one degree and now studies at a university for a more advanced degree

US a student who has a master's degree or PhD and now studies for a more advanced degree

postgraduate adjective

a postgraduate degree in mathematics

(Definition of “postgraduate” from the Cambridge Learner’s Dictionary © Cambridge University Press)