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
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
Approaching the frontier The performance of Chinese AI models is also increasing.
—
Kai Nicol-Schwarz,
CNBC,
7 July 2026
From the voice of the one whose body has become the only frontier left, the yodel becomes a site to abduct the abductee from her own abduction.
—
Literary Hub,
6 July 2026
The immersive frontier The third major component of this season’s upgrade may be its most future-facing.
—
Dave Brooks,
Los Angeles Times,
6 July 2026
But some fertility experts believe frontier AI could further boost the odds of a successful pregnancy.
—
Edna Bonhomme,
Scientific American,
6 July 2026
See All Example Sentences for frontier
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Kai Nicol-Schwarz,
CNBC,
7 July 2026
From the voice of the one whose body has become the only frontier left, the yodel becomes a site to abduct the abductee from her own abduction.
—
Literary Hub,
6 July 2026
The immersive frontier The third major component of this season’s upgrade may be its most future-facing.
—
Dave Brooks,
Los Angeles Times,
6 July 2026
But some fertility experts believe frontier AI could further boost the odds of a successful pregnancy.
—
Edna Bonhomme,
Scientific American,
6 July 2026
See All Example Sentences for frontier
Cite this Entry
“Frontier.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/frontier. Accessed 7 Jul. 2026.
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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