theologian vs bookman

theologian and bookman both are nouns.

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

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

theologian: someone who is learned in theology or who speculates about theology
bookman: a learned person; someone who by long study has gained mastery in one or more disciplines

Other hypernyms of theologian include scholar, scholarly person.

theologian (noun)	bookman (noun)
someone who is learned in theology or who speculates about theology	a learned person; someone who by long study has gained mastery in one or more disciplines