c.1320, abbreviation of
chicken (q.v.), extended to human offspring (often in alliterative pairing
chick and child) and used as a term of endearment. As slang for "young woman" it is first recorded 1927 (in "Elmer Gantry"), supposedly from U.S. black slang, in British use by c.1940, popularized by Beatniks late 1950s.
Chicken in this sense is from 1711. Sometimes c.1600-1900
chicken was taken as a plural,
chick as a singular (cf.
child/children) for the domestic fowl.