side ef·fect/ˈ· ·ˌ·/ n [C] 1 an effect, usually a bad effect, that a drug has on your body in addition to curing illness or pain 〔药物的〕副作用: The most common side effect is a slight fever. 最常见的副作用是会发低烧。 2 an unexpected result of an activity, situation, or event 〔活动、事态或事件的〕意外后果