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
The advertising frontier represents yet another example of how crypto casinos operate in regulatory gray areas, constantly adapting to reach audiences globally from day one.
—Boaz Sobrado, Forbes.com, 30 Apr. 2025
Phoenix 1, a prototype spacecraft built by German company Atmos Space Cargo, rode to the final frontier on April 21 via SpaceX's Bandwagon-3 rideshare mission.
—Mike Wall, Space.com, 29 Apr. 2025
My favorite moment of his, may be his opening song, a folk tune sung on a frontier night.
—Jackson McHenry, Vulture, 28 Apr. 2025
But the next frontier of Kanopy’s growth is reaching people who don’t yet have a library card and might be inclined to sign up for one or seek one out.
—Brian Welk, IndieWire, 24 Apr. 2025
See All Example Sentences for frontier
Examples are automatically compiled from online sources to
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Boaz Sobrado, Forbes.com, 30 Apr. 2025
Phoenix 1, a prototype spacecraft built by German company Atmos Space Cargo, rode to the final frontier on April 21 via SpaceX's Bandwagon-3 rideshare mission.
—Mike Wall, Space.com, 29 Apr. 2025
My favorite moment of his, may be his opening song, a folk tune sung on a frontier night.
—Jackson McHenry, Vulture, 28 Apr. 2025
But the next frontier of Kanopy’s growth is reaching people who don’t yet have a library card and might be inclined to sign up for one or seek one out.
—Brian Welk, IndieWire, 24 Apr. 2025
See All Example Sentences for frontier
Cite this Entry
“Frontier.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/frontier. Accessed 3 May. 2025.
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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