postdoc vs scholar

postdoc and scholar both are nouns.

Word	Noun	Adjective	Verb	Adverb
postdoc	Yes	No	No	No
scholar	Yes	No	No	No

As nouns, scholar is a hypernym of postdoc; that is, scholar is a word with a broader meaning than postdoc:

postdoc: a scholar or researcher who is involved in academic study beyond the level of a doctoral degree
scholar: a learned person; someone who by long study has gained mastery in one or more disciplines

Other hypernyms of postdoc include investigator, research worker, researcher, bookman, scholarly person.

postdoc (noun)	scholar (noun)
a scholar or researcher who is involved in academic study beyond the level of a doctoral degree	a learned person; someone who by long study has gained mastery in one or more disciplines
a grant that funds postdoctoral study or research	someone (especially a child) who learns (as from a teacher) or takes up knowledge or beliefs
	a student who holds a scholarship