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


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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 Over the summer, Poland, Lithuania and Latvia declared states of emergency over the inflows of migrants, sending military, police and border guards to the border frontier. Laurence Norman, WSJ, 8 Oct. 2021 The wildcat notes, which once fueled frontier cities’ economies, fell into disuse. Declan Harty, Fortune, 7 Oct. 2021 Afterward, still in his Butch Cassidy costume, Bob Ferguson is relaxing on the porch of the Irma Hotel, a frontier landmark founded by Buffalo Bill Cody. David Montgomery, Washington Post, 7 Oct. 2021 After robbing the bank, Nat and company return to Redwood City, a frontier town bursting with color — which is also no accident. Peter Debruge, Variety, 6 Oct. 2021 This is the newest frontier in the ongoing parenting difficulties during a pandemic. Patricia Fersch, Forbes, 1 Oct. 2021 As westward expansion began, the circus followed after the pioneers who were opening up the frontier. Randy Dotinga, The Christian Science Monitor, 29 Sep. 2021 Once a frontier and battlefield between the FARC and government forces, now the River Pato is a neutral place where civilians, ex-FARC and even on occasion the army, row together. Steph Dyson, CNN, 28 Sep. 2021 Creamer was one of the earliest frontier gunsmiths to specialize in making them. David Buie,, 26 Sep. 2021

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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Time Traveler for frontier

Time Traveler

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

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Dictionary Entries Near frontier

front-foot rule



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Statistics for frontier

Last Updated

13 Oct 2021

Cite this Entry

“Frontier.” Dictionary, Merriam-Webster, Accessed 21 Oct. 2021.

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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

More from Merriam-Webster on frontier

Nglish: Translation of frontier for Spanish Speakers

Britannica English: Translation of frontier for Arabic Speakers Encyclopedia article about frontier


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