From Biology-Online Dictionary | Biology-Online Dictionary


1. To convert (the skin of an animal) into leather, as by usual process of steeping it in an infusion of oak or some other bark, whereby it is impregnated with tannin, or tannic acid (which exists in several species of bark), and is thus rendered firm, durable, and in some degree impervious to water.

The essential result in tanning is due to the fact that the tannins form, with gelatins and albuminoids, a series of insoluble compounds which constitute leather. Similar results may be produced by the use of other reagents in place of tannin, as alum, and some acids or chlorides, which are employed in certain processes of tanning.

2. To make brown; to imbrown, as by exposure to the rays of the sun; as, to tan the skin.

Origin: F. Tanner, LL. Tannare. See Tan.

1. The bark of the oak, and some other trees, bruised and broken by a mill, for tanning hides; so called both before and after it has been used. Called also tan bark.

2. A yellowish-brown colour, like that of tan.

3. A brown colour imparted to the skin by exposure to the sun; as, hands covered with tan.

(Science: botany) Tan bed, a bed made of tan; a bark bed. Tan pickle, the liquor used in tanning leather. Tan spud, a spud used in stripping bark for tan from trees. Tan [[stove 577 ]]. See Bark stove, under Bark. Tan vat, a vat in which hides are steeped in liquor with tan.

Origin: F. Tan, perhaps fr. Armor. Tann an oak, oak bar; or of Teutonic origin; cf. G. Tanne a fir, OHG. Tanna a fir, oak, MHG. Tan a forest. Cf. Tawny.