Green’s Dictionary of Slang

1. (Aus./N.Z.) a derog. term (or nickname) for a Maori or Aborigine; also adj.

1866		Age (Melbourne) 31 Dec. 5/6: The hundred yards backward race was won by Tarpot, beating Barrass, the only white competitor who could go with him.
1894		Truth (Sydney) 20 May. 1/6: There are ‘Tarpots,’ ‘Charcoals,’ and ‘Day and Martins’ all over the continent.
1936		‘Banjo’ Paterson Shearer’s Colt 81: Tarpot Tommy, a station black, who had been driving the ducks, rode up and laughed at him just as though he were a common person and not the owner of several stations and a gold-mine.
1949		F. Sargeson I Saw in My Dream 120: Wally said that if he was Mr Anderson he’d never let the tarpots inside the shed with their lousy sheep. [Ibid.] 211: Jerry’s a local tarpot. Oh, a maori! Anna said. I love maoris.
1963		D. Adsett Magpie Sings 88: Isabel did not say how, when at school, she had taken a leading part in the teasing of Maori kids by chanting ‘Tar pot! Tar pot! Who fell in the tar pot!’ [DNZE].
1976		R. Morrieson Pallet on the Floor 49: All these tarpots are too cunning to turn their back on themselves.
1993		Detroit Free Press (MI) 31 Oct. 6H/2: In the evenings we circle chairs around the fire to [...] tell stories. Not so different from Tarpot’s grandfather.

2. (US) a black child.

1882		Nat. Police Gaz. (NY) 24 June 2/4: ‘How old are you?’ said an ancient dame to a grinning little tar-pot.
1983		I.L. Allen Lang. of Ethnic Conflict 47: Color Allusions, Other than ‘Black’ and ‘Negro’: […] tar-baby [often nigger-tar-baby. Also tar-pot. All mean a child].