surveillance
/sɜːˈveɪləns/noun
mass noun
- close observation, especially of a suspected spy or criminal监视; 看守（间谍嫌疑人或疑犯）：
he found himself put under surveillance by British military intelligence.
他发现自己处于英国军事情报机构的监视之下。
词源
early 19th cent.: from French, from sur- 'over' + veiller 'watch' （from Latin vigilare 'keep watch'）.