From Longman Dictionary of Contemporary Englishtartartar‧tar /ˈtɑːtə $ ˈtɑːrtər/ noun 1 [uncountable]HBH a hard substance that forms on your teeth2 [countable] British English informalANGRY someone who has a violent temper She’s a real tartar.
Examples from the Corpus
tartar• Combine flour, soda, salt and cream of tartar in medium mixing bowl and add to creamed mixture, beating well.• The ingredients of this particular concoction included garlic, mustard seed, tamarind and cream of tartar.Origin tartar (1300-1400) Medieval Latin tartarum 