perimeter
- 01 B1 Intermediate
the total distance around the outside of a shape.
the total length of the boundary of a closed two-dimensional figure. Countable in mathematical contexts.
Simple“To find the perimeter of a square, you add the lengths of all four sides together.”
In context“The architect calculated the perimeter of the foundation to determine the exact quantity of concrete required for the retaining wall.”
Synonyms - 02 B2 Upper Intermediate
the outer edge or border of a specific area, like a building or a park.
the outermost limits or boundary of a physical area or complex.
Simple“Security guards patrol the perimeter of the airport every hour.”
In context“The protesters gathered just outside the perimeter of the embassy, held back by a line of temporary steel fencing.”
- 03 C1 Advanced
a protected line around a military position.
a fortified boundary or defensive line established to protect a military installation or position.
Simple“The soldiers worked quickly to secure the perimeter before nightfall.”
In context“The commander ordered the troops to reinforce the western perimeter, fearing that the dense forest provided too much cover for an enemy advance.”
Synonymsdefensive lineboundary - 04 C2 Proficiency
a tool used by doctors to measure how far you can see to the sides.
an instrument used in ophthalmology to map the extent and sensitivity of a patient's visual field.
Simple“The eye doctor used a perimeter to check if the patient had lost any side vision.”
In context“Automated perimeters have largely replaced manual testing for detecting early signs of glaucoma in clinical practice.”
From Latin perimetros, Ancient Greek περίμετρος (perímetros). Equivalent to peri- + meter.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.