perimeter
puh-RIM-ih-ter
/pəˈrɪmɪtə(r)/
The continuous outer boundary of a specific area, land, or building.
In security, the perimeter is the very first line of defense, representing the physical boundary of the property (like a fence line or yard edge).
The story behind the word. The word 'perimeter' comes from the Greek perimetron, combining peri- (meaning 'around') and metron (meaning 'measure'). Historically, it was used in geometry to calculate the total distance around a shape. In military and security contexts, it evolved to mean the outer boundary that must be defended to protect the interior.
Word relationships
- boundary: A general term for any dividing line, while perimeter specifically refers to the continuous outer edge of a closed geometric area or property.
- border: Usually refers to political divisions between countries or states, whereas perimeter is used for localized properties or shapes.
- center: The middle point of an area, whereas the perimeter is the outermost edge.
- interior: The inside area of a building or shape, which lies within the perimeter.
Commonly confused with
- border: A perimeter is the continuous outer boundary of a specific closed area, while a border is a political or geographic dividing line.
Word family
- perimetric (adjective): Relating to a perimeter or boundary.
Collocations
- outer perimeter
- secure the perimeter
- perimeter fence
- perimeter security
Example sentences
- "The guards regularly patrol the outer perimeter of the estate." Patrolling the outer boundaries.
Memory hook
Think of 'perimeter' as 'pear-rim-meter'—measuring the rim around a pear-shaped garden. The perimeter is the rim around your property.
When not to use
Do not use 'perimeter' to describe the interior walls or hallways of a house.
Fun facts
- In military strategy, a 'perimeter defense' is a secure line of defense established around an entire force or position, with no exposed flanks.
Related words
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