A yellowish-brown color. Bark of oak or other trees, bruised and used as a source of tannin for converting hides into leather. (of a pale-skinned person or their skin) become brown or browner after exposure to the sun. Convert (animal skin) into leather by soaking in a liquid containing tannic acid, or by the use of other chemicals. Beat (someone) repeatedly, especially as a punishment. Of a yellowish-brown color. Tangent.