a system of weights used chiefly in compounding and dispensing drugs: 20 grains = 1 scruple (§); 3 scruples = 1 dram (?); 8 drams = 1 ounce (oz.); 12 ounces = 1 pound. The grain, ounce, and pound are the same as in troy weight, the grain alone being the same as in avoirdupois weight.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.