Quote Originally Posted by Secura View Post
I've never understood how that term became so widespread
OED:

3. transf.

a. Applied to human offspring; = chicken n.1 2; esp. in alliteration with child. Sometimes as a term of endearment (see quot. a1616).
c1320 Seuyn Sag. (W.) 2159 He is the fendes chike.
c1380 Sir Ferumbras (1879) l. 4331 He semeþ ful wel þe deuels chyke, y-sprong of þe pyt of helle.
1611 R. Cotgrave Dict. French & Eng. Tongues at Bremant, Hee hath nor child nor chicke to care for.
a1616 Shakespeare Tempest (1623) v. i. 320 My Ariel; chicke That is thy charge.
1630 T. Dekker Second Pt. Honest Whore i. ii. 81, I haue no wife, I haue no child, haue no chick.
1648 R. Herrick Hesperides sig. I5v, And so dresse him up with Love, As to be the Chick of Jove.
1870 W. Morris Earthly Paradise II. iii. 280 He‥had no chick or child to bless his house.


b. A girl; a young woman. slang (orig. U.S.).
1927 S. Lewis Elmer Gantry vii. 114 He didn't want to marry this brainless little fluffy chick.
1957 C. MacInnes City of Spades i. v. 31 There stood‥Muriel's sister. But what a difference from the little chick!
1959 News Chron. 12 Aug. 4/3 Beatniks and their ‘chicks’—palefaced girls wearing pony-tail hair-dos and toreador pants.
1971 It. 12–16 June 16/2 Jackie, always a ‘with-it chick’.