postgraduate
noun [ C ] uk/ˌpəʊstˈɡrædʒ.u.ət/ us/ˌpoʊstˈɡrædʒ.u.ət/ (US usually graduate)
研究生
a student who has already received one degree and is studying at a university for a more advanced degree
postgraduate
adjective [ before noun ] uk/ˌpəʊstˈɡrædʒ.u.ət/ us/ˌpoʊstˈɡrædʒ.u.ət/ (US usually graduate)
研究生（课程）的
used to refer to university studies or students at a more advanced level than a first degree
postgraduate studies/research 研究生的学习／研究
a postgraduate degree in microbiology 微生物学研究生学位