tartan n.

1510s, from Latin Tyrius "of Tyre," (Latin Tyrus), island-city in the Levant, from Greek Tyros, from Hebrew/Phoenician tzor, literally "rock, rocky place." Especially in reference to Tyrian purple, a dye chemically similar to indigo, made there in ancient times from certain mollusks (Murex brandaris).

"bitartrate of potash" (a deposit left during fermentation), late 14c., from Old French tartre, from Medieval Latin tartarum, from late Greek tartaron "tartar encrusting the sides of wine casks," perhaps of Semitic origin, but if so the exact source has not been identified; Arabic is unlikely because of the early date of the word in Latin. The purified substance is cream of tartar. Used generally in 17c. of encrustations from liquid contact; specific meaning "encrustation on teeth" (calcium phosphate) is first recorded 1806.