frontier vs bailiwick

frontier and bailiwick both are nouns.

Word	Noun	Adjective	Verb	Adverb
frontier	Yes	No	No	No
bailiwick	Yes	No	No	No

As nouns, bailiwick is a hypernym of frontier; that is, bailiwick is a word with a broader meaning than frontier:

frontier: an undeveloped field of study; a topic inviting research and development
bailiwick: a branch of knowledge

Other hypernyms of frontier include discipline, field, field of study, study, subject, subject area, subject field.

frontier (noun)	bailiwick (noun)
an undeveloped field of study; a topic inviting research and development	a branch of knowledge
a wilderness at the edge of a settled area of a country	the area over which a bailiff has jurisdiction
an international boundary or the area (often fortified) immediately inside the boundary