mop作verb [ T ]意为用拖把拖洗；擦去（脸上的）汗水。
mop sth up（用布或拖把）吸干净；用拖把擦去。=to use a piece of cloth or a mop to remove liquid from the surface of something。
mop up还有“结束，完成”的意思。

【例句】
He mopped the bathroom floor.
他拖了浴室地板。

There's milk on the floor over there - could you get a cloth and mop it up?
那边地板上有牛奶——你能拿块布把它擦干净吗？