kitten (n.)

late 14c., kitoun, "the young of a domesticated cat," probably from an Anglo-French variant of Old French chaton, chitoun (Old North French caton) "little cat," a diminutive of chat "cat," from Late Latin cattus (see cat (n.)). In playful use, "a young girl, a sweetheart," from 1870. As a verb, "bring forth kittens," late 15c. To have kittens "lose one's composure" is from 1908.