Green’s Dictionary of Slang

(US black) of hair, having been straightened; having hair that has been straightened; thus unconked, describing hair that is in its natural state.

1941		‘Digg Mee’ ‘Observation Post’ in N.Y. Age 10 May 9/5: You can get a hat to wear on your ‘konked’ down hair .
1944		D. Burley Orig. Hbk of Harlem Jive 21: Blessings on thee Little Square, / Barefoot Cat with the unconked hair.
1953		L. Durst Jives of Dr. Hepcat (1989) 7: Let’s look in on a couple of of jitterbugs talking about their hair and a certain way that hair is being fixed today [...] called conked.
1953		W. Fisher Waiters 50: A conked-haired zoot-suiter lounging in the doorway.
1957		H. Simmons Corner Boy 13: Grease trailed [...] from the straight, sticky patches of his conked hair.
1960		C. Cooper Jr Scene (1996) 22: The slickness of his konked head looked hard and clublike.
1965		(con. 1940s) Malcolm X Autobiog. (1968) 129: A wiry, brown-skinned, conked fellow [...] greeted me.
1965		C. Himes Cotton Comes to Harlem (1967) 78: Conk-haired black cotton pickers, clad in overalls that resembled Italian-tailored suits.
1968		N. Heard Howard Street 85: He had his hair conked.
1969		C. Himes Blind Man with a Pistol (1971) 52: One conk-haired joker [...] said offensively, ‘What mother-raping fight?’.
1969		S. Greenlee Spook who Sat by the Door (1972) 45: All them dirty, conk-headed niggers with their African and down-home ways.
1972		Milner & Milner Black Players 72: Tim has a round baby face, a broad-shouldered muscular six-foot frame, and an elaborate conked hairdo.
1980		E. Folb Runnin’ Down Some Lines 141: It was still not uncommon to hear teenagers talking about getting their hair conked.
1981		E. Bunker Little Boy Blue (1995) 113: Blacks had ‘conked’ or processed hair.
1983		(con. 1966) T. White Catch a Fire 211: Rita [...] had had her hair conked and styled for the occasion [i.e. Haile Selassie’s visit to Jamaica].
1988		(con. 1940s) C. Bram Hold Tight (1990) 145: The conked hair beneath the pomade felt coarse.
1992		D. Pinckney High Cotton (1993) 53: It was only a matter of time before he had his hair konked and rolled up in one of those damp scarves favored by thugs on bad corners.
1995		J. Stahl Permanent Midnight 347: This rail-thin, fully conked young cat.
2003		G. Tate Midnight Lightning 44: The [...] documentary of that performance shows Hendrix, gingerly conked hair looking like a mess of black flames, sporting a ruffled shirt.