observer/əbˋzɝvɚ; əbˈzɜːvə/n [C] 1 someone who goes to a meeting, class, event etc to officially watch or check what is happening〔会议﹑事件等的〕观察员;〔课堂的〕旁听者: a group of UN observers in Bosnia 驻波斯尼亚的一个联合国观察员小组2 someone who watches or notices something 观察者﹔目击者