Noun frontier has 3 senses
- frontier - a wilderness at the edge of a settled area of a country; "the individualism of the frontier in Andrew Jackson's day"
--1 is a kind of wilderness, wild
- frontier - an international boundary or the area (often fortified) immediately inside the boundary
--2 is a kind of boundary, bound, bounds
--2 has particulars: Triple Frontier
- frontier - an undeveloped field of study; a topic inviting research and development; "he worked at the frontier of brain science"
--3 is a kind of discipline, subject, subject area, subject field, field, field of study, study, bailiwick, branch of knowledge
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