 was considered by some to be based on these galoshes, but it was fashionable to wear them zipped. So the girls would just walk around with these galoshes on zips and flop, flop, flop around everywhere, which I suppose was not very ladylike at the time. But the real etymology of flapper is much earlier. In the 19th century, it was used in Britain to mean prostitute, and by the end of the century, of course, it meant any high-spirited teenage girl.