periphery

noun

pe·​riph·​ery pə-ˈri-f(ə-)rē 

plural peripheries

1

: the perimeter of a circle or other closed curve

also : the perimeter of a polygon

2

: the external boundary or surface of a body

3

a

: the outward bounds of something as distinguished from its internal regions or center : confines

b

: an area lying beyond the strict limits of a thing

Synonyms

• perimeter
• edge
• confines
• circumference
• boundary
• border
• edging

Examples of periphery in a Sentence

the dogs are confined by an invisible electronic fence that runs along the periphery of the yard

Recent Examples on the Web

Getty Images The landscape of women’s health is shifting from the periphery to the main stage. —Priya Oberoi, Forbes.com, 15 Sep. 2025

The highest tap fees are concentrated among towns and cities on the periphery that secured more expensive water rights later and whether by necessity or choice, built their own water and sewer system. —Aldo Svaldi, Denver Post, 15 Sep. 2025

The host proto-cluster – or group of galaxies in the early stages of formation – that’s home to the jet is on the periphery of our Milky Way galaxy. —Eric Lagatta, USA Today, 12 Sep. 2025

Protecting the Plaza Bowl In years past, any attempt to breach what is known as the Plaza bowl — with building heights no more than three stories at the center and gradually moving higher toward its periphery — had been met with opposition and even anger. —Eric Adler, Kansas City Star, 12 Sep. 2025

Word History

Etymology

Middle French peripherie, from Late Latin peripheria, from Greek periphereia, from peripherein to carry around, from peri- + pherein to carry — more at bear

First Known Use

circa 1568, in the meaning defined at sense 1

Kids Definition

periphery

noun

pe·​riph·​ery pə-ˈrif-(ə-)rē 

plural peripheries

1

: the boundary or surface of a body or figure

2

: the outer or outermost part

Medical Definition

periphery

noun

pe·​riph·​ery pə-ˈrif-(ə-)rē 

plural peripheries

1

: the outward bounds of something as distinguished from its internal regions or center

2

: the regions (as the sense organs, the muscles, or the viscera) in which nerves terminate