Tartar refers to:

• the Tatars, an ethnic group in present-day Russia (this term formerly extended to nearly all Central Asian and Mongolian ethnic groups)
• Mongolian tribe Tartars in 12th century
• hardened dental plaque (see calculus (dental)).
• the Torrance High School mascot, the Tartars

You may also be looking for:

• tartar sauce,
• salts of tartaric acid:
  • cream of tartar,
  • tartar emetic .