1. the outer boundaries or edges of an area or shape
2. the distance around the outside of a geometric figure
Usage: mathematics
3. the outer limits of a defended area or territory
Usage: military; security

Examples

• Security guards patrol the perimeters of the building at night.
• The students calculated the perimeters of various triangles and rectangles.
• The fence marks the perimeters of our property.
• Military forces established defensive perimeters around the base.
• The park’s perimeters are clearly marked with signs.
• We measured the perimeters of the garden beds before buying mulch.
• The police set up perimeters around the crime scene.