- ounce, troy ounce, apothecaries' ounce - a unit of apothecary weight equal to 480 grains or one twelfth of a pound
--1 is a kind of apothecaries' unit, apothecaries' weight; troy unit
--1 is a part of troy pound, apothecaries' pound
--1 has parts: pennyweight; dram, drachm, drachma