Green’s Dictionary of Slang

1. as a coin.

2. (Aus./US, also browny) a brown-skinned person, an Asian; in Aus. an aborgine, a Japanese; in N.Z. a Maori.

1851		Bell’s Life in Sydney 1 Mar. 2/7: If your whitey browney hit im, I’ll kill her.
1876		J. Miller First Fam’lies in the Sierras 85: Washee-Washee will lie [...] but he steals no more, do you, little brownie?
1899		New Oxford Item (Gettysburg, PA) 7/1: This phenomenon of artillery fire is a good deal of a tragical puzzle to the little browny [i.e. a Filipino].
1900		Bulletin (Sydney) 21 Apr. 24/3: A horsey young Maori undertook to engineer a grey stallion in a trot for a brother brownie recently.
1900		Bulletin (Sydney) 26 May 12/3: One might as well look for individuality in a bunch of grapes. At length introductions broke up the cluster, and Miss Ruby Madden fell into conversation with the dapper little brownies [i.e. Japanese].
1913		H. Lawson ‘The Kids’ in Roderick (1972) 809: When I was teaching a Native school down in South Island (Maoriland) years ago, my little brownies used to shout out manfully — and girlfully.
1930		S.O. Barker ‘Flete’ in Botkin Folk-Say 134: Covered wagons from whose peek-a-boo ends black-eyed, roundfaced brownies peer.
1966		W. Wilson LBJ Brigade (1967) 60: We ain’t here ta defend or capture anythin, we’re here ta kill the brownies.

3. (Aus., a cake made of flour, fat and sugar, and filled with raisins or currants; thus N.Z.) brownie-gorger, a shearer.

1893–5		H. Lawson ‘Two Sundowners’ in Roderick (1972) 99: He saw the cook and got some ‘brownie’, a bit of cooked meat and a packet of baking powder.
1900		H. Lawson ‘Joe Wilson’s Courtship’ in Roderick (1972) 541: Here’s some tea and brownie.
1903		J. Furphy Such is Life 65: I was having a drink of tea and a bit of brownie in the men’s hut.
1908		J. Gunn We of the Never-Never (1962) 232: Several yards of sweet currant ‘brownie’.
1910		C.E.W. Bean On the Wool Track 170: ’E couldn’t cook. ’E couldn’t even bake a blanky brownie.
1926		J. Devanny Butcher Shop 17: Here, jerk the brownie along.
1936		I.L. Idriess Cattle King 268: There’s no sauce. And that brownie—you would be lucky if you found a currant in it!
1945		Baker Aus. Lang. 80: Then there is the brownie, fattie and tommy, all mixed in the same way as the damper with the addition of sugar, currants and fat.
1958		W.E. Harney Content to Lie in the Sun 36: A drink of tea and a piece of ‘brownie’ (bush cake).
1977		T. Ronan Mighty Men on Horseback 14: Stoking his mouth with a brownie.
1984		J. Carson in Ammon Working Lives 157: I enjoyed my meal of chops, damper and brownie.
2003		McGill Reed Dict. of N.Z. Sl. 35: brownie Cocoa or currant damper; treacle gingerbread among tramps; a brownie gorger is a shearer.

4. pertaining to the anus.

5. (US) a small (usu. chocolate) cake impregnated with hashish or marijuana [brownie, a trad. US biscuit].

1971

E.E. Landy Underground Dict (1972) 40: brownie n. Brownie made with marijuana baked in it.