From the ArcaMax Publishing, Vocabulary Newsletter:
http://www.arcamax.com/news/vocabulary/s-360479-186970
avoirdupois \av-uhr-duh-POIZ; AV-uhr-duh-poiz\ (noun) - 1 :
Avoirdupois weight, a system of weights based on a pound containing 16
ounces or 7,000 grains (453.59 grams). 2 : Weight; heaviness; as, a
person of much avoirdupois.
"The Yemeni eased his avoirdupois upon the leather chair at his desk,
cracked his knuckles, and typed in a rapid sequence -- a password, no
doubt." -- Robert Ludlum, 'The Bancroft Strategy'
Avoirdupois is from Middle English avoir de pois, "goods sold by
weight," from Old French aveir de peis, literally "goods of weight,"
from aveir, "property, goods" (from aveir, "to have," from Latin
habere, "to have, to hold, to possess property") + de, "from" (from
the Latin) + peis, "weight," from Latin pensum, "weight."