fron·​tier | \ ˌfrən-ˈtir How to pronounce frontier (audio) , ˈfrən-ˌtir, frän-ˈtir, ˈfrän-ˌtir How to pronounce frontier (audio) \

Definition of frontier

1a : a border between two countries the frontier between Canada and the U.S.
b obsolete : a stronghold on a frontier
2a : a region that forms the margin of settled or developed territory were sent on an expedition to explore the western frontier
b : the farthermost limits of knowledge or achievement in a particular subject frontiers in immunology
c : a line of division between different or opposed things the frontiers separating science and the humanities— R. W. Clark
d : a new field for exploitative or developmental activity … the brain lies before us as one of the last scientific frontiers here on earth.— Robert Klitzman

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Other Words from frontier

frontier adjective

Synonyms for frontier


border, borderland, march

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Examples of frontier in a Sentence

the frontier between Canada and the U.S. They were sent on an expedition to explore the western frontier.

Recent Examples on the Web

Widespread sewage recycling could be the next frontier. Sasha Harris-lovett And David Sedlak, WSJ, "From Toilet to Tap: What Cities Need to Overcome to Make That Happen," 17 May 2019 Brands like Wrangler and L.L. Bean are aligned with narratives that play on myths of the West and the frontier, which are notably the embraced by the Republican right. Roxanne Adamiyatt, Town & Country, "Cambridge Analytica Targeted L.L. Bean and Wrangler Customers in the 2016 Presidential Election," 30 Nov. 2018 While Google Maps has most of the great outdoors pretty well mapped, indoor mapping is the next great frontier. Ron Amadeo, Ars Technica, "Google adds indoor positioning to Android’s Find My Device," 21 Nov. 2018 Alcorta said training the public is the last frontier. Meredith Cohn,, "Training can help people stop bleeding from traumatic injuries, experts say," 21 Apr. 2018 Asia is the next frontier for the PGA and having a young player from any of those countries (but particularly China and India) would have long-term effects on golf’s place in the global sports world. Chris Chase, For The Win, "Will Tiger Woods make this the best Masters ever?," 3 Apr. 2018 High schools are the next frontier, with many students more than happy to sport big-name brands. Joel Odom,, "Notre Dame vs. Mississippi State: TV channel, live stream, score updates for NCAA women's basketball championship," 1 Apr. 2018 The next debatable frontier could be moving the December early signing period to August prior to a prospect's senior year. Ron Higgins,, "National Signing Day now a shadow of its bloated, theatrical self," 7 Feb. 2018 With gene therapy surfacing as perhaps the most imminent frontier, working inside the double helixes could render many of our medical modalities laughable. Katie Kosma, Longreads, "Gene Therapy: God Discusses Its Future Possibilities," 6 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'frontier.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of frontier

15th century, in the meaning defined at sense 1a

History and Etymology for frontier

Middle English fronter, from Anglo-French frountere, fronter, from front

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Statistics for frontier

Last Updated

7 Jun 2019

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Time Traveler for frontier

The first known use of frontier was in the 15th century

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More Definitions for frontier



English Language Learners Definition of frontier

: a border between two countries
: a distant area where few people live
: the limits of knowledge in a particular field


fron·​tier | \ ˌfrən-ˈtir How to pronounce frontier (audio) \

Kids Definition of frontier

 (Entry 1 of 2)

1 : a border between two countries
2 : the edge of the settled part of a country



Kids Definition of frontier (Entry 2 of 2)

: of, living in, or situated in the frontier frontier towns frontier families

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Comments on frontier

What made you want to look up frontier? Please tell us where you read or heard it (including the quote, if possible).


to move with exaggerated bouncy motions

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