[fruhn-teer, fron-; also, esp. British, fruhn-teer]


the part of a country that borders another country; boundary; border.
the land or territory that forms the furthest extent of a country's settled or inhabited regions.
Often frontiers.
  1. the limit of knowledge or the most advanced achievement in a particular field: the frontiers of physics.
  2. an outer limit in a field of endeavor, especially one in which the opportunities for research and development have not been exploited: the frontiers of space exploration.
Mathematics. boundary(def 2).


of, relating to, or located on the frontier: a frontier town.

Origin of frontier

1350–1400; Middle English frounter < Old French frontier, equivalent to front (in the sense of opposite side; see front) + -ier -ier2
Related formsfron·tier·less, adjectivefron·tier·like, adjectivesem·i·fron·tier, nountrans·fron·tier, adjective

Synonym study

1. See boundary. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for frontier

Contemporary Examples of frontier

Historical Examples of frontier

British Dictionary definitions for frontier



  1. the region of a country bordering on another or a line, barrier, etc, marking such a boundary
  2. (as modifier)a frontier post
US and Canadian
  1. the edge of the settled area of a country
  2. (as modifier)the frontier spirit
(often plural) the limit of knowledge in a particular fieldthe frontiers of physics have been pushed back

Word Origin for frontier

C14: from Old French frontiere, from front (in the sense: part which is opposite); see front
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for frontier

c.1400, from Old French frontier "prow of a ship, front rank of an army" (13c.), noun use of adjective frontier "facing, neighboring," from front "brow" (see front (n.)).

Originally the front line of an army, sense of "borderland" is first attested early 15c. In reference to North America, from 1670s; later with a specific sense:

What is the frontier? ... In the census reports it is treated as the margin of that settlement which has a density of two or more to the square mile. [F.J. Turner, "The Frontier in American History," 1920]

Frontiersman is from 1782.

Online Etymology Dictionary, © 2010 Douglas Harper