—n. 1. a moral or ethical consideration or standard that acts as a restraining force or inhibits certain actions.
2. a very small portion or amount.
3. a unit of weight equal to 20 grains (1.295 grams) or 1/3 of a dram, apothecaries' weight.
4. an ancient Roman unit of weight equivalent to 1/24 of an ounce or 1/288 of an as or pound. Cf. as2 (def. 2).