a piece of equipment or a program that can be added to a computer system to improve its performance （计算机系统上的）附加设备；插件；附加程序◆Most PC companies offer digital cameras as an add-on. 大部分个人电脑公司提供数码照相机作为附加设备。◆Control your PC's interaction with add-on devices. 控制个人计算机和插件的连接。⨁add-on devices / hardware / memory / software 附加设备／硬件／记忆体／软件
an extra part or service that can be joined to a product, system or service to improve it, especially sth extra that can be sold to a customer 附加产品；附加系统；附加服务◆People pay extra for add-ons to basic insurance cover. 人们在投保基本险外，往往还另外付费投保附加险。⨁add-on device / module / package 附加设备／模块／套件