a counterweight to a vertically sliding window sash.
The Torturous Treadmill And Other Exercise Name OriginsLet's run down some of that hardware terminology and learn their interesting origin stories too!
Origin of sash weight
First recorded in 1730–40
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for sash weight
a weight used to counterbalance the weight of a sliding sash in a sash window and thus hold it in position at any height
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012