noun
Abbreviation of 医科大学の学生. Refers specifically to a student at a medical university, not a general medical trainee.
彼は医大生で、毎日解剖学の勉強をしている。
He is a medical student and studies anatomy every day.
Abbreviation of 医科大学 (いだいがく, medical university) + 生 (せい, student).