What is the origin of “flapper,” referring to a convention-defying
young woman of the '20s?
From Brewer’s Dictionary of 20th-Century Phrase and Fable:
“In the early years of the 20th century a term applied to a girl in her teens, now called a teenager, from her plaited pigtail tied at the end with a large bow. When stepping along the pigtail flapped her back. Subsequently her hair was ‘put up’ in a ‘bun’ or other hairstyle. By the 1920s the name was commonly applied to a young woman, or ‘bright young thing’.”
But this website says something about the reason they flapped was because they were hiding liquor:
Which is it?