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

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

frontier adjective

Synonyms

• border
• borderland
• march

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

Singh: In our opinion, health, animal health is the next frontier. —Fortune Editors, Fortune, 17 Apr. 2024

In today’s era, social media is the new frontier, and corporations are following suit. —Ebony Flake, Essence, 16 Apr. 2024

The Northwest Territory, between Pennsylvania and the Mississippi River, north of the Ohio River, was unsettled frontier. —Erin Couch, The Enquirer, 14 Apr. 2024

The Space Force is clearly preparing for an impending battle to take place in the final frontier. —Passant Rabie / Gizmodo, Quartz, 13 Apr. 2024

Myanmar’s military-run government is battling insurgencies on several fronts and has suffered a series of defeats in frontier areas since last October, when rebel groups launched a coordinated offensive near the Chinese border. —Reuters, NBC News, 11 Apr. 2024

The latest frontier in this research focuses on metabolic syndrome or diabetes. —Will Stone, NPR, 29 Mar. 2024

Many in the field have long believed these to be outdated and have been encouraging alternative efforts and new frontiers. —Julia Daye, Miami Herald, 3 Apr. 2024

VanDerveer, who turns 71 in June and is the winningest coach in college basketball, has given no indication of walking away with the program facing a new frontier. —Jerry McDonald, The Mercury News, 30 Mar. 2024

Word History

Etymology

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

First Known Use

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

Kids Definition

frontier

noun

fron·​tier ˌfrən-ˈti(ə)r  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