WordNet
apothecaries' ounce
n. a unit of apothecary weight equal to 480 grains or one twelfth of a pound [syn: ounce, troy ounce]
Wikipedia
Apothecaries' ounce
Apothecaries' ounce is a unit of weight of medicine used in pharmacy. One unit of apothecaries ounce is equal to 30g in metric system. It is abbreviated using the symbol ℥.