frontier
noun
fron·tier
ˌfrən-ˈtir 
ˈfrən-ˌtir,
frän-ˈtir,
ˈfrän-ˌtir
1
a
: a border between two countries
the frontier between Canada and the U.S.
b
obsolete
: a stronghold on a frontier
2
a
: 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
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
Robert Klitzman
frontier
adjective
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
Some critics say that while the lab is doing important safety research, its creation of frontier AI models still heightens dangerous competitive pressures.
—Billy Perrigo/san Francisco, TIME, 30 May 2024
Moscow surprised Ukraine on May 10 when its troops poured across the northeastern border, punching through Ukrainian defenses and seizing villages close to the frontier.
—Matthew Mpoke Bigg, New York Times, 26 May 2024
With the new frontier of schools rapidly approaching, local advocates launched the Academy for Local Leadership earlier this year to train a group of fellows on how school districts operate.
—Alysa Guffey, Chicago Tribune, 26 May 2024
In the midst of the archetypical frontier town, Tom Rourke fuels himself by drinking, doping and writing.
—Lorraine Berry, Los Angeles Times, 15 May 2024
See all Example Sentences for frontier 
Billy Perrigo/san Francisco, TIME, 30 May 2024
Moscow surprised Ukraine on May 10 when its troops poured across the northeastern border, punching through Ukrainian defenses and seizing villages close to the frontier.
—Matthew Mpoke Bigg, New York Times, 26 May 2024
With the new frontier of schools rapidly approaching, local advocates launched the Academy for Local Leadership earlier this year to train a group of fellows on how school districts operate.
—Alysa Guffey, Chicago Tribune, 26 May 2024
In the midst of the archetypical frontier town, Tom Rourke fuels himself by drinking, doping and writing.
—Lorraine Berry, Los Angeles Times, 15 May 2024
See all Example Sentences for frontier
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'frontier.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Dictionary Entries Near frontier
Cite this Entry
“Frontier.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/frontier. Accessed 9 Jun. 2024.
Copy CitationKids Definition
frontier
noun
fron·tier
ˌfrən-ˈti(ə)r
frän-
frän-
1
: a border between two countries
2
a
: a region that forms the edge of the settled part of a country
b
: the outer limits of knowledge or achievement
the frontiers of science
frontier
adjective
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