"The word 'sweater' is disgusting!" Dom declared out of the blue a few minutes ago. (We've got a high proportion of out-of-the-blue declarers here at The Stranger.) "Think about it—a word for something you wrap around your body to make you sweat."
That seemed improbably literal. There are so many false cognates in English etymology (example: "amendable" from Latin minare "to drive cattle with shouts" and "amenity" from Latin amoenitatem "delightfulness, pleasantness"). "Sweater" must have come from some Proto-Germanic or Old Saxon word for warmth. Or something.
But no. Ladies and gentlemen, the etymology of "sweater":
"woolen vest or jersey, originally worn in rowing," 1882, from earlier sweaters "clothing worn to produce sweating and reduce weight" (1828), from sweat (v.).
Turns out that Dom is correct. "Sweater" is kind of gross.