perimeter

[ puh-rim-i-ter ]

noun

1. a line bounding or marking off an area:

   The police created a perimeter with caution tape around the crime scene.

2. the outermost limits:

   Under the new regulations, the smoke-free area for playgrounds and sports areas extends 20 meters from the perimeter of each site.

3. Geometry.
   1. the border or outer boundary of a two-dimensional figure.
   2. the length of such a boundary.
4. Military. a fortified boundary that protects a troop position.
5. Ophthalmology. an instrument for determining the peripheral field of vision.
6. Often the perimeter. Basketball.
   1. Also called three-point line. a semicircular line on a basketball court surrounding the basket, outside of which field goals are worth three points rather than two. three-pointer ( def ).
   2. the area outside this line (often used attributively):

      There's no player in the NBA who puts more pressure on opposing defenses from the perimeter than him.

      The team needs an efficient point guard with a great perimeter shot.

perimeter

/ ˌpɛrɪˈmɛtrɪk; pəˈrɪmɪtə /

noun

1. maths
   1. the curve or line enclosing a plane area
   2. the length of this curve or line
2. 1. any boundary around something, such as a field
   2. ( as modifier )

      a perimeter fence

      a perimeter patrol

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

perimeter

/ pə-rĭm′ĭ-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.

Derived Forms

• peˈrimetry, noun
• ˌperiˈmetrically, adverb
• perimetric, adjective

Other Words From

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

Word History and Origins

Origin of perimeter¹

First recorded in 1585–95; from French périmètre, from Latin perimetros (feminine), from Greek perímetron (neuter); equivalent to peri- + -meter

Word History and Origins

Origin of perimeter¹

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

Example Sentences

The area within the Mountain fire perimeter has seen eight significant wildfires in the last four decades.

From Los Angeles Times

The burglary took place at around 23:45 on Sunday 13 October, and was reported to have involved scaling a six-foot perimeter fence and escaping by breaking through a gate with a stolen vehicle.

From BBC

The groups use a designated walking path that traces the stadium's perimeter.

From BBC

Most recently, the 2023 South and 2019 Maria fires burned thousands of acres in the western section of the Mountain fire’s perimeter.

From Los Angeles Times

Homeowners should also consider a defensive perimeter around their properties to present fire from spreading easily to a home.

From Los Angeles Times

Related Words

• boundary
• confines
• edge
• fringe
• periphery