n.a system of weights used for precious metals and gemstones; based on a 12-ounce pound and an ounce of 480 grains
同义词：troy
英汉双解大词典
troy weight(alsotroy)
1.
N（名词）
a system of weights used for precious metals and gemstones, based on the grain, which is identical to the avoirdupois grain. 24 grains = 1 pennyweight; 20 pennyweights = 1 (troy) ounce; 12 ounces = 1 (troy) pound 金衡制