Green’s Dictionary of Slang

1. (US black) straightened hair; a hairstyle that involves effort to achieve.

1964		R. Abrahams Deep Down In The Jungle 38: The men have taken to having their hair straightened in a pompadour style, called a ‘process’.
1968		J. Colebrook Cross of Lassitude 174: They get cleaned up, cured of clap, well fed, and come out with a process.
1973		D. Goines Street Players 8: Patting his hair lightly, pushing the process back in place.
1980		E. Folb Runnin’ Down Some Lines 141: Don’t care how the young lady wear her hair. She kin get down with a fonky natural, [...] else she kin have a righteous process.
1993		Eble Campus Sl. Oct. 4: process – hairstyle that took some work to produce [...] ‘Hey, man, don’t mess with my process.’.
2002		(con. ealy 1960s) R. Gordon Can’t Be Satisfied 181: ‘[H]e had on a fine suit, a nice process, a little narrow mike, little narrow tie, sharp shoes, and he was sweating away’.

2. attrib. use of sense 1.

1966		C. Keil Urban Blues 27: Backstage at the Regal Theatre in Chicago ‘process rags’ are everywhere in evidence among the male performers.
1984		J. Ellroy Blood on the Moon 17: Liquor stores, night clubs, process parlors and storefront churches interspersed with vacant lots.
2000		F.X. Toole Rope Burns 184: That old white man gonna tear up you process ass.

3. the chemical-based product used to achieve the process.

1964

L. Hairston ‘The Winds of Change’ in Clarke Harlem, USA (1971) 319: Sonny rubbed the process in so thick with his rubber gloves, it started stingin’ a little.