tartar
n[U]
1 hard chalky deposit that forms on the teeth 牙垢; 牙石. Cf 参看 plaque2.2 reddish deposit that forms on the inside of a cask in which wine is fermented 酒石(形成於酒的发酵桶内侧者).
tartar n person who has a violent temper or is difficult to deal with 脾气暴躁的人; 难对付的人.