[ fruhn-teer, fron-; also, esp. British, fruhn-teer ]
/ frʌnˈtɪər, frɒn-; also, esp. British, ˈfrʌn tɪər /


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.

Nearby words

  1. frontenac,
  2. frontenac et palluau,
  3. frontenis,
  4. fronter,
  5. frontes,
  6. frontier orbital,
  7. frontiersman,
  8. frontierswoman,
  9. frontis,
  10. frontispiece

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

British Dictionary definitions for frontier


/ (ˈfrʌntɪə, frʌnˈtɪə) /


  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


Online Etymology Dictionary, © 2010 Douglas Harper