Source : Webster's Revised Unabridged Dictionary (1913)

Tan \Tan\, v. t.
   To thrash or beat; to flog; to switch. [Colloq.]

Tan \Tan\, v. t. [imp. & p. p. {Tanned}; p. pr. & vb. n.
   {Tanning}.] [F. tanner, LL. tannare. See {Tan}, n.]
   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.

   Note: 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.

Tan \Tan\, n. [Chin.]
   See {Picul}.

Tan \Tan\, n. [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}.]
   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 color, like that of tan.

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

   {Tan bed} (Hort.), 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}. See {Bark stove}, under {Bark}.

   {Tan vat}, a vat in which hides are steeped in liquor with
      tan.

Tan \Tan\, a.
   Of the color of tan; yellowish-brown.

   {Black and tan}. See under {Black}, a.

Tan \Tan\, v. i.
   To get or become tanned.

Source : WordNet®

tan
     adj : of a light yellowish-brown color
     [also: {tanning}, {tanned}, {tannest}, {tanner}]

tan
     n 1: a browning of the skin resulting from exposure to the rays
          of the sun [syn: {suntan}, {sunburn}, {burn}]
     2: a light brown [syn: {topaz}]
     3: ratio of the opposite to the adjacent side of a right-angled
        triangle [syn: {tangent}]
     [also: {tanning}, {tanned}, {tannest}, {tanner}]

tan
     v 1: treat skins and hides with tannic acid so as to convert them
          into leather
     2: get a tan, from wind or sun [syn: {bronze}]
     [also: {tanning}, {tanned}, {tannest}, {tanner}]