Source : Webster's Revised Unabridged Dictionary (1913)

Sorrel \Sor"rel\, a. [F. saur, saure, OF. sor, sore, probably of
   Teutonic origin; cf. D. zoor dry, LG. soor; the meaning
   probably coming from the color of dry leaves. See {Sear}, a.,
   and cf. {Sorel}.]
   Of a yellowish or redish brown color; as, a sorrel horse.

Sorrel \Sor"rel\, n.
   A yellowish or redish brown color.

Sorrel \Sor"rel\, n. [F. surelle, fr. sur sour, fr. OHG. s?r
   sour. See {Sour}.] (Bot.)
   One of various plants having a sour juice; especially, a
   plant of the genus {Rumex}, as {Rumex Acetosa}, {Rumex
   Acetosella}, etc.

   {Mountain sorrel}. (Bot.) See under {Mountain}.

   {Red sorrel}. (Bot.)
   (a) A malvaceous plant ({Hibiscus Sabdariffa}) whose acid
       calyxes and capsules are used in the West Indies for
       making tarts and acid drinks.
   (b) A troublesome weed ({Rumex Acetosella}), also called
       {sheep sorrel}.

   {Salt of sorrel} (Chem.), binoxalate of potassa; -- so called
      because obtained from the juice of {Rumex Acetosella}, or
      {Rumex Axetosa}.

   {Sorrel tree} (Bot.), a small ericaceous tree ({Oxydendrum
      arboreum}) whose leaves resemble those of the peach and
      have a sour taste. It is common along the Alleghanies.
      Called also {sourwood}.

   {Wood sorrel} (Bot.), any plant of the genus Oxalis.

Source : WordNet®

sorrel
     adj : of a light brownish color [syn: {brownish-orange}]
     n 1: any plant or flower of the genus Oxalis [syn: {oxalis}, {wood
          sorrel}]
     2: any of certain coarse weedy plants with long taproots,
        sometimes used as table greens or in folk medicine [syn: {dock},
         {sour grass}]
     3: East Indian sparsely prickly annual herb or perennial
        subshrub widely cultivated for its fleshy calyxes used in
        tarts and jelly and for its bast fiber [syn: {roselle}, {rozelle},
         {red sorrel}, {Jamaica sorrel}, {Hibiscus sabdariffa}]
     4: large sour-tasting arrowhead-shaped leaves used in salads
        and sauces [syn: {common sorrel}]
     5: a horse of a brownish orange to light brown color