tooth复数形式是teeth。
tooth常用作名词，意思是“牙齿；齿；牙；齿状部分”，tooth的基本意思是“牙，齿”，其复数形式是teeth，但由tooth构成的复合词在变成复数时，则只需将主体名词变成复数形式。
词汇搭配：
drill a tooth.钻牙
fill a tooth.补牙
get one's teeth.长牙
have a tooth out.拔牙
front tooth.前牙，门齿
milk tooth.乳齿
saw tooth.锯齿
wisdom tooth.智齿
短语搭配：
tooth profile.齿形；齿廓
tooth surface.齿面；轮齿表面
long in the tooth.岁口大的（马）；年迈的，年老的
tooth decay.蛀牙；龋齿；齵齿
tooth root.[医]齿根；[医]牙根
双语例句：
1、Her tooth was extracted under local anaesthetic.
她的牙齿是局部麻醉拔出的。
2、He chipped off a piece of his tooth.
他锛缺了一点牙齿。
3、I need to have two teeth filled.
我有两颗牙要补。
4、The residents are fighting tooth and nail to stop the new development.
居民为制止新的建房开发计划正在全力以赴进行斗争。
5、Choose an essay topic that you can really get your teeth into.
选择一个你可以真正悉心钻研的论文题目。
6、When did she cut her first tooth?
她什么时候长出的第一颗牙？
7、A high proportion of five-year-olds have teeth in poor condition.
五岁儿童牙齿不健康的比例高。
8、The dentist may decide that the wisdom teeth need to be extracted.
牙医可能会认为智齿需要拔掉。
9、They took a plaster cast of the teeth for identification purposes.
他们做了这副牙的石膏模型作鉴别之用。
10、He's got a front tooth missing.
他有一颗门牙掉了。