avoirdupois measure

avoirdupois measure

(av″ĕr-dĕ-poyz′, -pwa′) [Fr. avoir du pois, to have (some) weight]
A system of weighing or measuring articles in which 7000 grains equal 1 lb.
References in periodicals archive ?
As a unit of measure, the ounce referred to 'a unit of weight equal to (a) one-twelfth of a pound in troy and apothecaries' measure, equal to 480 grains (= 31.1 grams); (b) one-sixteenth of a pound in avoirdupois measure (= ~ 28.3 grams)' (OED).