Английский Этимологический словарь - sweat (v.)

- O.E. swжtan "perspire, work hard." The noun is from O.E. swat "sweat" (which became M.E. swote, but altered under the influence of the verb), from P.Gmc. *swaita, from PIE *sweid-/*swoid-. Sweatshirt first recorded 1929. Sweater "woolen vest or jersey, originally worn in rowing" first recorded 1882, from earlier sweaters "clothing worn to produce sweating and reduce weight" (1828); sweater girl is attested from 1940; Lana Turner (1920-95) was the first. Sweat equity is from 1968.