tooth 
英 [tuːθ]  美 [tuθ] 
n. 牙齿，齿状物

v. 给…装齿；啮合

例句：
If a tooth feels very loose, your dentist may recommend that it be taken out. 

如果某颗牙松动得厉害，牙医会建议把它拔掉。

to brush your teeth 

刷牙

to have a tooth out 

拔牙