scruple

1

A unit of mass in the apothecaries' weight system in the English-speaking world, 18th – 20th century, = 20 grains = ¹/₃ drachm or dram, exactly 1.295 978 2 grams.

In the United Kingdom, use of the scruple in trade ended on January 1, 1971.¹ The symbol for the scruple is, which is very ancient, appearing in manuscripts of the Roman era. It is sometimes followed by an S, which stands for the Latin semis, half. So S is half a scruple.

1. Weights and Measures Act, 1963, a prohibition specifically reaffirmed in the Weights and Measures Acts of 1976 and 1985.

2

A unit of liquid capacity in British apothecaries' measure, about 1.184 milliliters.