perimeter
B2Formal, Academic, Technical
Definition
Meaning
The continuous line forming the boundary of a closed geometric figure; the outer limits or edge of an area or object.
In broader usage, the outermost boundary or edge of any defined space, real or abstract, such as a property, security zone, or area of interest. In military/security contexts, it specifically refers to a defensive boundary established around a position.
Linguistics
Semantic Notes
Strongly associated with geometry, security, and measurement. Implies a continuous, enclosing boundary rather than just a general edge. Often used when precision or defensibility is conceptually relevant.
Dialectal Variation
British vs American Usage
Differences
Usage is highly consistent. Slight preference for 'perimeter fence' in UK security contexts, while US may use 'perimeter wall' or 'perimeter barrier' more interchangeably.
Connotations
Neutral in both, but carries a stronger security/military connotation in contemporary American English due to frequent use in news and defense contexts.
Frequency
Slightly more frequent in American English within security, sports (basketball), and real estate contexts.
Vocabulary
Collocations
Grammar
Valency Patterns
the perimeter of [NP]a perimeter around [NP]on/at the perimeterinside/outside the perimeterVocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “tighten the perimeter”
- “a breach in the perimeter”
- “hold the perimeter”
Usage
Context Usage
Business
Referring to the physical boundaries of a site or the conceptual limits of a market or operational area. (e.g., 'We need to secure the business park perimeter.')
Academic
Primarily geometric. Used in mathematics, geography, architecture, and environmental science. (e.g., 'The perimeter of the polygon was calculated.')
Everyday
Used for describing the boundary of a garden, property, or sports field. (e.g., 'They planted a hedge around the perimeter of the garden.')
Technical
Essential in geometry, surveying, security systems, military tactics, and sports analytics (e.g., basketball 'perimeter shooting').
Examples
By Part of Speech
verb
British English
- (Rare as verb) The estate was carefully perimetred with a new hedge.
American English
- (Rare as verb) The troops will perimeter the camp before nightfall.
adverb
British English
- (Not standard) The sensors were placed perimeter.
American English
- (Not standard) The guards were stationed perimeter.
adjective
British English
- The perimeter fence required urgent maintenance.
- Perimeter security measures were heightened.
American English
- He's a great perimeter shooter on the basketball court.
- Perimeter lighting was installed around the warehouse.
Examples
By CEFR Level
- The farmer put a fence around the perimeter of his field.
- We walked around the perimeter of the small lake.
- To find the perimeter of a rectangle, add the lengths of all four sides.
- Security cameras monitor the entire perimeter of the building.
- Archaeologists established a working perimeter around the dig site to protect the finds.
- The fire spread quickly, forcing officials to expand the evacuation perimeter.
- The novel's plot operates within the strict perimeter of a single day, employing a classical unity of time.
- Critics argue that the new policy pushes the perimeter of acceptable state surveillance.
Learning
Memory Aids
Mnemonic
Imagine a PERfectly measured fence around the outer edge of your property—that's your PERIMETER. Think 'PERI' (around) + 'METER' (measure).
Conceptual Metaphor
BOUNDARY AS CONTAINER; SECURITY AS WALL; LIMIT AS LINE.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not confuse with 'периметр' (which is a direct cognate and correct) and 'окружность' (which specifically means 'circumference' of a circle). 'Периметр' in Russian is also highly associated with the siege of Leningrad ('The Road of Life' was inside the 'perimeter'), adding a historical weight not present in default English usage.
Common Mistakes
- Using 'perimeter' for an open or non-enclosing edge (e.g., 'the perimeter of the cliff').
- Confusing 'perimeter' (1D length of boundary) with 'area' (2D space inside).
- Misspelling as 'perimiter'.
Practice
Quiz
In which context is the word 'perimeter' LEAST likely to be used?
FAQ
Frequently Asked Questions
'Perimeter' is the general term for the total length of the boundary of any closed shape. 'Circumference' is specifically the perimeter of a circle. 'Girth' often refers to the distance around a cylindrical object like a tree or a person's waist.
Yes, metaphorically. You can talk about the 'perimeter of the law' (its limits) or 'the perimeter of our understanding' (the boundary of what is known), though this is more advanced usage.
It's technically correct but less common than 'border' or 'frontier'. 'Perimeter' suggests a more precise, measurable, or defensible line, so it might be used in military or scientific contexts (e.g., 'the country's maritime perimeter'), but 'border' is standard for political boundaries.
A player, typically a guard or forward, who operates primarily on the outer edges (the perimeter) of the offensive zone, focusing on long-range shots (like three-pointers) rather than play near the basket (the 'post' or 'paint').