Flapper

Flappers had their own slang, with terms like "snugglepup" (a man who frequents petting parties) and "barney-mugging" (sex). Their dialect reflected their promiscuity and drinking habits; "I have to go see a man about a dog" often meant going to buy whiskey, and a "handcuff" or "manacle" was an engagement or wedding ring. Also reflective of their preoccupations, they had many ways to express approval, such as "That's so Jake" or "That's the bee's knees," or a more popular one, "the cat's pajamas."

Many terms still in use in modern American English slang originated as flapper slang, such as "big cheese," meaning an important person; "to bump off," meaning to murder; and "baloney," meaning nonsense. Other terms have become definitive of the Prohibition era, such as "speakeasy," meaning a place to purchase illegal alcohol and "hooch," which means liquor.

Called garçonne in French ("boy" with a feminine suffix), flapper style made them look young and boyish.

Then I found out there were MORE

Modern Girls (モダンガール, modan gaaru) were a group of Japanese women who followed Westernized fashion and lifestyle in the 1920s. These rebellious moga were the Japanese equivalent of America's flappers, India's vamps, Germany's neue Frauen, France's garçonnes, or China's modeng xiaojie. Modern Girls often lived in the cities, were financially and emotionally independent, chose their own suitors, and were apathetic towards politics.