avoirdupois weight: Meaning and Definition of

avoirdupois' weight"

Pronunciation: [key]
  1. the system of weights in British and U.S. use for goods other than gems, precious metals, and drugs: 27 grains = 1 dram; 16 drams = 1 ounce; 16 ounces = 1 pound; 112 pounds (Brit.) or 100 pounds (U.S.) = 1 hundredweight; 20 hundredweight = 1 ton. The pound contains 7000 grains. Abbr.: av.; avdp.; avoir.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.