medical student vs pupil

medical student and pupil both are nouns.

Word	Noun	Adjective	Verb	Adverb
medical student	Yes	No	No	No
pupil	Yes	No	No	No

As nouns, pupil is a hypernym of medical student; that is, pupil is a word with a broader meaning than medical student:

Other hypernyms of medical student include educatee, student.

medical student (noun)	pupil (noun)
a student in medical school	the contractile aperture in the center of the iris of the eye; resembles a large black dot
	a learner who is enrolled in an educational institution
	a young person attending school (up through senior high school)