a lock or curl of hair brought forward over the forehead.
"curl or lock of hair over the forehead," 1890, originally a style among soldiers, of unknown origin. Perhaps connected with quiff "a puff or whiff of tobacco smoke" (1831, originally Southern U.S.), held to be a variant of whiff (q.v.). (http://dictionary.reference.com/browse/quiff)
"Zadak is a youthful forty-three, with a sharp quiff and an unlined face, and was a comedy nerd before he became a comedy manager: hanging around the Second City Chicago, moving to L.A. to study screenwriting, hoping to be an improv guy himself."
- Zadie Smith, "Brother from another mother: Key and Peele's chameleon comedy", 23 February and 2 March 2015 The New Yorker (http://www.newyorker.com/magazine/2015/02/23/brother-another-mother)