guard /ɡɑ:d/ I. vt.& vi. 1. 守卫，保卫: guard one’s life 保护生命 2. 防止，防犯(against): guard against disease 预防疾病 ‖II. n.［c］守卫；哨兵，警卫员：keep guard 守望，放哨; stand guard 站岗 The guards are on duty at the palace.这些警卫在宫门口值班。off one’s guard不值班；疏忽, 大意：I was off my guard and made no suitable reply.我没提防，因此没有作出适当的回答。on guard 站岗：The soldier was on guard all night. 士兵整夜担任警戒。on one’s guard 警惕，提防：Be on your guard against pickpockets. 谨防扒手。