An apothecaries unit is a historical system of measurement used in the field of pharmacy for the weighing of drugs and medicines. It is also referred to as apothecaries weight, pharmacy weight, or troy weight. Other synonyms that are commonly used for apothecaries unit include grain weight, scruple weight, and dram weight. These terms are often used interchangeably in various medical contexts to denote a unit of measurement that is widely accepted in the field. Despite the introduction of metric systems of measurement, apothecaries unit has continued to be used in some countries for the dosing of medications.