Green’s Dictionary of Slang

1. a Native American woman.

1878–9

A. Garcia Tough Trip Through Paradise (1977) 68: Even Beaver Tom, the squaw Beau Brummel, was saying we had to get away from this bunch of brunettes.

2. a black person; also as adj.

1884		Life 3 Apr. 186: ‘Dat ain’t none o’ yo’ bithniss,’ replied the brunette [HDAS].
1896		Ade Artie (1963) 67: You’re a brunette, ain’t you?
1915		S. Ford Torchy, Private Sec. 5: ‘Is she in, Cephas?’ says I to the brunette Jamaican [...] who juggles the elevator.
1928		N.I. White Amer. Negro Folk-Songs 314: [reported from Auburn, AL, 1915–16] A blondy woman, a blondy woman / Make a po’ man go to jail, / But a brunette woman will make / A tadpole fight a whale.