college man vs student

college man and student both are nouns.

Word	Noun	Adjective	Verb	Adverb
college man	Yes	No	No	No
student	Yes	No	No	No

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

Other hypernyms of college man include educatee, pupil.

college man (noun)	student (noun)
a student (or former student) at a college or university	a learner who is enrolled in an educational institution
	someone (especially a child) who learns (as from a teacher) or takes up knowledge or beliefs