Note: Do not rely on this information. It is very old.
Sweating
Sweating, in certain trades, strictly means sub-contracting - i.e. instead of hiring workers directly, "putting the work out" through middle-men, who make their profits by cutting down the wages paid. More loosely, it is applied to the system of paying for piecework at so low a rate that starvation can only be kept off by overwork.