avoirdupois

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.

Claydon . . . was happy to admit that he has shed some avoirdupois.
-- Mel Webb, "Claydon's loss leads to net gain", Times (London), February 18, 2000

Yet until middle age and avoirdupois overtook her, Mary was no slouch.
-- John Updike, "How to Milk a Millionaire", New York Times, March 29, 1987

Tired of putting on and taking off the same five pounds? Don't delay, buy this book today -- and watch yourself shed both respectability and surplus avoirdupois!
-- David Galef, "J. Faust's Guide to Power' And Other Self-Help Classics", New York Times, December 18, 1994

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."