1. (Abbreviation: cwt) A former unit of weight used in the UK, equal to 112 lbs; 20 cwt equal 1 long ton (2240 lbs). It has been largely replaced by metric units; many bags that used to contain 1 cwt of material now contain 50 kilos. 1 cwt = 50.8 kilograms. Under the Weights and Measures Act 1985 and the EU directive on metric measures adopted into British law in January 2000 it is no longer legal to use the hundredweight in trade.
2. A unit of weight used in the USA, equal to 100 lbs; 20 hundredweights = 1 short ton (2000 lbs).