1. the outer edge or boundary of something
2. an area of activity that is less important than the main area

Examples

• The new shopping mall was built on the periphery of the city.
• Small villages dotted the periphery of the forest.
• He remained on the periphery of the political movement.
• The company’s research division operates on the periphery of its main business.
• Houses on the periphery of town are usually less expensive.
• She felt like she was always on the periphery of her friend group.
• The security guards patrolled the periphery of the building.