apothecaries' weight

American  

noun

1. a system of weights used chiefly in compounding and dispensing drugs: 20 grains = 1 scruple (℈); 3 scruples = 1 dram (dr); 8 drams = 1 ounce); 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.

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apothecaries' weight British  

noun

1. a system of weights, formerly used in pharmacy, based on the Troy ounce, which contains 480 grains. 1 grain is equal to 0.065 gram

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apothecaries' weight Scientific  

/ ə-pŏth′ĭ-kĕr′ēz /

1. A system of weights used in pharmacy and based on an ounce equal to 480 grains and a pound equal to 12 ounces. It has been largely replaced by measures of the metric system.

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Etymology

Origin of apothecaries' weight

First recorded in 1755–65