In the ancient Persian language, a tree is called “dauru”. As the language evolved and passed from Avestan to Pahlavi, it became known as “dar”. “Daruk” refers to a small tree or shrub, and as it seems, before the discovery of chemical medicine, all medicines were obtained from bushes and shrubs. The word “daruk” in Old Pahlavi became “darog” in Pahlavi, and with this form, it entered European languages, where it is known as “droga” in Latin,  “drug” in English and “drogue” in French.