to rub something with a rough cloth, brush, or paper until its surface is smooth, or clean and shiny

Rub the wood down with fine sandpaper until it is smooth. 用细砂纸把木头磨光滑。

We rubbed the walls down with soap and hot water. 我们用肥皂和热水把墙面擦干净了。

to use a cloth to dry an animal or person

I used a towel to rub the dog down after his bath. 我给狗洗完澡后用毛巾把它的毛擦干。