A peripheral activity or issue is one which is not very important compared with other activities or issues.
例句
Companies are increasingly keen to contract out peripheral activities like training...公司越来越倾向于把像培训这样的非核心业务外包出去。...peripheral and boring information...无关紧要的无聊信息
ADJ
周围的；边缘的
Peripheral areas of land are ones which are on the edge of a larger area.
例句
...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
N-COUNT
（计算机）外围设备，外部设备
Peripherals are devices that can be attached to computers.
例句
...peripherals to expand the use of our computers.扩展计算机用途的外围设备... peripheral products for the basic computer.普通电脑的外围设备