[ puh-rim-i-ter ]
See synonyms for: perimeterperimetric on

  1. the border or outer boundary of a two-dimensional figure.

  2. the length of such a boundary.

  1. a line bounding or marking off an area.

  2. the outermost limits.

  3. Military. a fortified boundary that protects a troop position.

  4. Ophthalmology. an instrument for determining the peripheral field of vision.

Origin of perimeter

1585–95; <French périmètre<Latin perimetros (feminine) <Greek perímetron (neuter). See peri-, -meter

Other words from perimeter

  • pe·rim·e·ter·less, adjective
  • pe·rim·e·tral, per·i·met·ric [per-uh-me-trik], /ˌpɛr əˈmɛ trɪk/, per·i·met·ri·cal, adjective
  • per·i·met·ri·cal·ly, adverb
  • pe·rim·e·try, noun

Words that may be confused with perimeter

Words Nearby perimeter Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use perimeter in a sentence

British Dictionary definitions for perimeter


/ (pəˈrɪmɪtə) /

  1. maths

    • the curve or line enclosing a plane area

    • the length of this curve or line

    • any boundary around something, such as a field

    • (as modifier): a perimeter fence; a perimeter patrol

  1. a medical instrument for measuring the limits of the field of vision

Origin of perimeter

C16: from French périmètre, from Latin perimetros; see peri-, -meter

Derived forms of perimeter

  • perimetric (ˌpɛrɪˈmɛtrɪk) or perimetrical, adjective
  • perimetrically, adverb
  • perimetry, noun

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

Scientific definitions for perimeter


[ pə-rĭmĭ-tər ]

  1. The sum of the lengths of the segments that form the sides of a polygon.

  2. The total length of any closed curve, such as the circumference of a circle.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.