bibliographer vs bookman

bibliographer and bookman both are nouns.

Word	Noun	Adjective	Verb	Adverb
bibliographer	Yes	No	No	No
bookman	Yes	No	No	No

As nouns, bookman is a hypernym of bibliographer; that is, bookman is a word with a broader meaning than bibliographer:

bibliographer: someone trained in compiling bibliographies
bookman: a learned person; someone who by long study has gained mastery in one or more disciplines

Other hypernyms of bibliographer include scholar, scholarly person.

bibliographer (noun)	bookman (noun)
someone trained in compiling bibliographies	a learned person; someone who by long study has gained mastery in one or more disciplines