Tartar is a single English word used for several unrelated concepts in dentistry, food and history. The intended meaning depends on context: it can denote hardened dental deposits, a chemical used in baking, names of dishes or condiments, or an older European label for peoples and regions of Central Eurasia.
Dental tartar
Dental tartar, also called calculus, is mineralized dental plaque that forms on teeth and along the gumline. Saliva supplies calcium and phosphate that gradually harden plaque into a rough surface that attracts more bacterial growth. Because tartar bonds to the tooth surface it cannot be removed by routine brushing and requires professional removal by scaling. If not managed, tartar contributes to gum inflammation (gingivitis), bad breath and can be a factor in periodontitis and tooth loss. Prevention emphasizes regular brushing, interdental cleaning, fluoride toothpaste and periodic dental checkups.
Culinary tartar and cream of tartar
Cream of tartar is the common name for potassium hydrogen tartrate, a crystalline byproduct of wine fermentation that can deposit inside casks. In cooking it functions as an acidulant and stabilizer: it helps stabilize whipped egg whites, prevents sugar crystallization in syrups, and when combined with baking soda produces carbon dioxide for leavening. The word also appears in food names: tartar sauce is a cold mayonnaise-based condiment often served with fried fish, and steak tartare (or simply "tartare") is a dish of finely chopped raw meat or fish seasoned and served cold.
Historical and ethnographic use
From the medieval period into early modern European writing, "Tartar" (and the related geographic label "Tartary") was used broadly and imprecisely for many peoples and regions of the Eurasian steppe. This usage often conflated different Turkic and Mongolic groups. Modern scholarship and contemporary communities prefer specific ethnonyms such as "Tatar" for particular Turkic peoples; the older exonym is now regarded as outdated and imprecise.
Notes on language and usage
Because the senses are unrelated, readers should rely on context to determine meaning. In technical contexts use "dental calculus" or "calculus" for clarity, and "cream of tartar" or the chemical name when discussing cooking. When referring to peoples, prefer accurate contemporary names and be cautious of historical sources that used "Tartar" as a catch-all term.