Dictionary.net

• The system of weights used for gold, silver, precious stones, and in philosophical experiments, containing 5760 grains, divided into 12 ounces of 480 grains each. The Troy pound is less than the Avoirdupois, or pound of commerce, which has 7000 grains, divided into 16 ounces of 437.5 grains each.

1899 - The american dictionary of the english language.
By Daniel Lyons