In Britain, it's a pullover sweater; in America, it's a sleeveless dress worn over a blouse
I had known jumper only as a sort 
of sleeveless dress usually worn over a blouse, what the Oxford... [DOC] [TLE] British/American Clothing Confusion: Wearing a Fanny Pack Around ... [PAR] In America, it became a sleeveless, collarless dress worn over a blouse ... dress 
in the U.K.) and in Britain it came to be synonymous with pullover (a term ... 
Sweater first appeared in its current form in the United States sometime in the 
late... [DOC] [TLE] English vocabulary for clothes and shoes - english-at-home.com [PAR] Clothes.