[ fruhn-teer, fron-; also, especially British, fruhn-teer ]
/ frʌnˈtɪər, frɒn-; also, especially 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.

Origin of frontier

1350–1400; Middle English frounter<Old French frontier, equivalent to front (in the sense of opposite side; see front) + -ier-ier2

synonym study for frontier

1. See boundary.


fron·tier·less, adjectivefron·tier·like, adjectivesem·i·fron·tier, nountrans·fron·tier, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences 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