1 a living thing, too small to be seen without a special instrument(microscope), that causes disease in people, animals and plants 病毒，过滤性病毒（小得要用显微镜才能看见的病原体）: HIV, the virus that is thought to cause Aids 人体免疫缺损病毒─一般认为是引致艾滋病的病毒 to catch a virus 感染病毒 ☞Look at bacteria and germ (1). 参看bacteria及germ(1)。

2 (computing计算机技术) instructions that are put into a computer program in order to stop it working properly and destroy information 电脑病毒；计算机病毒 ➔viral /ˈvaɪrəl ||; ˈvaɪrəl/ adj a viral infection 病毒感染