frontier

play
noun fron·tier \ ˌfrən-ˈtir , ˈfrən-ˌtir , frän-ˈtir , ˈfrän-ˌtir \

Definition of frontier

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

Examples of frontier in a Sentence

  1. the frontier between Canada and the U.S.

  2. They were sent on an expedition to explore the western frontier.

Recent Examples of frontier from the Web

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.

Origin and Etymology of frontier

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

frontier Synonyms

Synonyms
border, borderland, march
Related Words
no-man's-land

FRONTIER Defined for English Language Learners

frontier

play
noun

Definition of frontier for English Language Learners

  • : a border between two countries

  • : a distant area where few people live

  • : the limits of knowledge in a particular field


FRONTIER Defined for Kids

1

frontier

play
noun fron·tier \ ˌfrən-ˈtir \

Definition of frontier for Students

1 :a border between two countries
2 :the edge of the settled part of a country

2

frontier

adjective

Definition of frontier for Students

:of, living in, or situated in the frontier
  • frontier towns
  • frontier families


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