Thorn \Thorn\, n. [AS. [thorn]orn; akin to OS. & OFries. thorn,
   D. doorn, G. dorn, Dan. torn, Sw. t["o]rne, Icel. [thorn]orn,
   Goth. [thorn]a['u]rnus; cf. Pol. tarn, Russ. tern' the
   blackthorn, ternie thorns, Skr. t[.r][.n]a grass, blade of
   grass. [root]53.]
   1. A hard and sharp-pointed projection from a woody stem;
      usually, a branch so transformed; a spine.
      [1913 Webster]

   2. (Bot.) Any shrub or small tree which bears thorns;
      especially, any species of the genus Crataegus, as the
      hawthorn, whitethorn, cockspur thorn.
      [1913 Webster]

   3. Fig.: That which pricks or annoys as a thorn; anything
      troublesome; trouble; care.
      [1913 Webster]

            There was given to me a thorn in the flesh, the
            messenger of Satan to buffet me.      --2 Cor. xii.
                                                  7.
      [1913 Webster]

            The guilt of empire, all its thorns and cares,
            Be only mine.                         --Southern.
      [1913 Webster]

   4. The name of the Anglo-Saxon letter ?, capital form ?. It
      was used to represent both of the sounds of English th, as
      in thin, then. So called because it was the initial letter
      of thorn, a spine.
      [1913 Webster]

   Thorn apple (Bot.), Jamestown weed.

   Thorn broom (Bot.), a shrub that produces thorns.

   Thorn hedge, a hedge of thorn-bearing trees or bushes.

   Thorn devil. (Zool.) See Moloch, 2.

   Thorn hopper (Zool.), a tree hopper (Thelia crataegi)
      which lives on the thorn bush, apple tree, and allied
      trees.
      [1913 Webster]