In Greek: μαστίχα
Mastiha starts as a semi-transparent sap from lentisk trees (actually evergreen bushes) found only in certain areas of the Greek island of Chios. As resinous granules, it was the original chewing gum, and the name "mastiha" is the root word of "masticate," meaning "to chew."
At the market, look for "mastiha," "mastihi," or "mastic tears" and it might also be available in powdered form.
Mastiha is used as a spice in sweets and cooking, as a flavoring for liqueurs, and in soap-making, cosmetics, and toothpaste, among others. Recent evidence of its positive effect on ulcers has resulted in a boom in purchases by large pharmaceutical companies.