mopping-up
noun [ U ] uk/ˌmɒp.ɪŋˈʌp/ us/ˌmɑːp.ɪŋˈʌp/
清理；扫尾
the activity of dealing with a small number of people, problems, etc. that remain after most of them have been defeated or solved
The war was effectively over, although skirmishing and mopping-up went on for some time. 战争实际上结束了，不过一些小冲突和清理行动还持续了一段时间。
mopping-up operations 扫尾行动