steelyard definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a balance or scale consisting of a metal arm suspended off center from above: the object to be weighed is hung from the shorter end, and a sliding weight is moved along the graduated longer end until the whole arm balances
Origin: steel plush yard (in obsolete sense of “rod, bar”)
steelyard definition by American Heritage Dictionary
A balance consisting of a scaled arm suspended off center, a hook at the shorter end on which to hang the object being weighed, and a counterbalance at the longer end that can be moved to find the weight.
Origin: steel + yard1, rod.