librarian vs bibliothec

librarian and bibliothec both are nouns.

Word	Noun	Adjective	Verb	Adverb
librarian	Yes	No	No	No
bibliothec	Yes	No	No	No

As nouns, librarian and bibliothec are synonyms defined as:

librarian and bibliothec: a professional person trained in library science and engaged in library services

librarian (noun)	bibliothec (noun)
a professional person trained in library science and engaged in library services	a professional person trained in library science and engaged in library services