Source : Webster's Revised Unabridged Dictionary (1913)

Spiny \Spin"y\, a. [From {Spine}.]
   1. Full of spines; thorny; as, a spiny tree.

   2. Like a spine in shape; slender. ``Spiny grasshoppers sit
      chirping.'' --Chapman.

   3. Fig.: Abounding with difficulties or annoyances.

            The spiny deserts of scholastic philosophy. --Bp.
                                                  Warburton.

   {Spiny lobster}. (Zo["o]l.) Same as {Rock lobster}, under
      {Rock}. See also {Lobster}.

Spiny \Spin"y\, n.
   See {Spinny}.

Source : WordNet®

spiny
     adj : having or covered with protective barbs or quills or spines
           or thorns or setae etc.; "a horse with a short bristly
           mane"; "bristly shrubs"; "burred fruits"; "setaceous
           whiskers" [syn: {barbed}, {barbellate}, {briary}, {briery},
            {bristled}, {bristly}, {burred}, {burry}, {prickly}, {setose},
            {setaceous}, {thorny}]
     [also: {spiniest}, {spinier}]