Green’s Dictionary of Slang

1. dreadlocks.

1978		D. Hebdige Subculture 43: The rude boy crop was grown out and allowed to explode into an ethnic ‘Afro’ frizz, or plaited into ‘locks’ or ‘knots’ (the ubiquitous natty or knotty style).
1983		G. Tate ‘King Sunny Adé’ in Flyboy in the Buttermilk (1992) 59: This [...] white boy spots me and homeboy’s natty dreads on the way out the door.
1986		O. Senior ‘Ballad’ Summer Lightning 110: Everybody know that them big office and store in Kingston dont want no natty head pickney work with them.
1995		Francis-Jackson Official Dancehall Dict. 36: Natty 1. natty-dreadlocks.
2006		R. Antoni Carnival 235: I tell you, she let loose a vengeance pon me natty head like a bomb.

2. a person with dreadlocks.

1975		‘Big Youth’ ‘Natty no Jester’ 🎵 Cos natty dread no jester / He no wear no polyester.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 123/1: natty n. person with dreadlocks.
2005		R. Cea No Lights, No Sirens 38: [H]ad ‘Nat E. Dread’ gotten a shot off and punched a quarter-sized hole through my windpipe [etc].