WordNet sense 1 (a salt used especially in baking powder):

cream of tartar, potassium bitartrate, potassium hydrogen tartrate

WordNet sense 2 (a fiercely vigilant and unpleasant woman):

dragon

WordNet sense 3 (a member of the Mongolian people of central Asia who invaded Russia in the 13th century):

Tatar, Mongol Tatar

WordNet sense 4 (an incrustation that forms on the teeth and gums):

calculus, tophus