The Collaborative International Dictionary of English v.0.48:

Thorny \Thorn"y\, a. [Compar. Thornier; superl. Thorniest.]
   [Cf. AS. [thorn]orniht.]
   1. Full of thorns or spines; rough with thorns; spiny; as, a
      thorny wood; a thorny tree; a thorny crown.
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   2. Like a thorn or thorns; hence, figuratively, troublesome;
      vexatious; harassing; perplexing. "The thorny point of
      bare distress." --Shak.
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            The steep and thorny way to heaven.   --Shak.
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   Thorny rest-harrow (Bot.), rest-harrow.

   Thorny trefoil, a prickly plant of the genus Fagonia
      (Fagonia Cretica, etc.).
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