tan¹ / tan/ • n. 1. a yellowish-brown color: the overall color scheme of tan and cream. ∎  a golden-brown shade of skin developed by pale-skinned people after exposure to the sun.2. (also tan·bark / ˈtanˌbärk/ ) bark of oak or other trees, bruised and used as a source of tannin for converting hides into leather. ∎  (also spent tan) such bark from which the tannin has been extracted, used for covering the ground for walking, riding, children's play, etc., and in gardening.• v. (tanned, tan·ning) 1. [intr.] (of a pale-skinned person or their skin) become brown or browner after exposure to the sun: you'll tan very quickly in the pure air. ∎  [tr.] [usu. as adj.] (tanned) (of the sun) cause (a pale-skinned person or their skin) to become brown or browner: he looked tanned and fit.2. [tr.] convert (animal skin) into leather by soaking in a liquid containing tannic acid, or by the use of other chemicals.3. [tr.] inf., dated beat (someone) repeatedly, esp. as a punishment: “If Mickey touches a fishing net, I'll tan his hide!”• adj. of a yellowish-brown color: a tan baseball cap with orange piping. ∎  (of a pale-skinned person) having golden-brown skin after exposure to the sun: she looks tall, tan, and healthy.DERIVATIVES: tan·na·ble adj.tan·nish adj.tan² • abbr. tangent.

Tan. 1. Chin., ‘cinnabar’, the most important element in religious Taoism, in the pursuit of immortality. In Outer Alchemy, wai-tan, effort was devoted to purifying tan and converting it to gold, to prolong life. In Inner Alchemy, tan is understood to be the interactive energy of yin-yang produced by appropriate breathing. 2. The slip of paper which designates the sitting-place of a Zen monk for zazen. 3. Earth-bound component of the body in Zoroastrianism: see FRAVASI.

tan convert (skin) into leather by steeping in an infusion of astringent bark OE.; make brown by the sun XVI; colloq. (orig. tan a person's hide) thrash XVII. late OE. *tannian, in pp. ġetanned and agent-noun tannere (see -ER1), prob. — medL. tannāre; reinforced in ME. from OF. vb. tan(n)-er.
Hence sb. crushed bark of oak, etc. for tanning XVII; brown or tawny colour XIX. tanner OE. tannere (or later — OF. tanere). tannery XV.

tan (tæn) Maths. tangent