a dash (或 lick, touch) of the tarbrush [蔑语](混有)黑人(或印第安人)血统
英文词源
tarbrush (n.)
1711, from tar (n.1) + brush (n.1). To have a touch of the tarbrush "have a dash of African ancestry visible in the skin tone" (1796) was "a term of contempt from the West Indies" [Century Dictionary].
实用例句
1. You might have a touch of the tarbrush yourself.