Graduate Student, Grad Student
noun
Remember how you learned that 大学院 means "graduate school" and 大学生 means "college student?" Well smush them together and you have a graduate student!
だいがくいんせい
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
この図書館は大学院生に人気です。
This library is popular with graduate students.
大学院生の主な活動は研究です。
The main activities of graduate students is research.
大学院生は合コンで結構モテるらしいよ。
Apparently, graduate students are quite popular in group dates.