1. A tree or shrub armed with spines or sharp ligneous shoots; as the black thorn; white thorn etc. The word is sometimes applied to a bush with prickles; as a rose on a thorn2. A sharp ligneous or woody shoot from the stem of a tree or shrub; a sharp process from the woody part of a plant; a spine. thorn differs from prickle; the latter being applied to the sharp points issuing from the bark of a plant and not attached to the wood, as in the rose and bramble. But in common usage, thorn is applied to the prickle of the rose, and in fact the two words are used promiscuously. 4. In Scripture, great difficulties and impediments. I will hedge up thy way with thorns. Hosea 2.5. Worldly cares; things which prevent the growth of good principles. Matthew 13:7. THORN'-APPLE, noun [thorn and apple.] A plant of the genus Datura; a popular name of the Datura Stramonium, or apple of Peru. THORN'-BACK, noun [thorn and back.] A fish of the ray kind, which has prickles on its back.THORN'-BUSH, noun A shrub that produces thorns. THORN'-BUT, noun A fish, a but or turbot.THORN'-HEDGE, noun [thorn and hedge.] A hedge or fence consisting of thorn