/pəˈrɪf.ɚ.əl/

happening at the edge of something
外围的,边缘的

Something that is peripheral is not as important as something else:
The book contains a great deal of peripheral detail.

happening at the edge of something:
A figure came into my peripheral vision.

(specialist) connected with the outer edge of a particular area 外围的;周边的
the peripheral nervous system
周围神经系统
peripheral vision
周边视觉

Peripheral areas of land are ones which are on the edge of a larger area. [usu ADJ n]
//…peripheral regions beyond the reach of powerful rulers.
强大的统治者势力范围之外的边缘地区
//…urban development in the outer peripheral areas of large towns.
大城市外围地区的城市开发

computing
a piece of equipment that is connected to a computer 外围设备;外部设备
monitors, printers and other peripherals
显示器、打印机及其他外围设备

Integrated Peripherals 外围设备