1 a stiff sharp-pointed projection on a plant.
2 a thorn-bearing shrub or tree.
3 the name of an Old English and Icelandic runic letter, = th.
Phrases and idioms:
on thorns continuously uneasy esp. in fear of being detected. thorn-apple
1 a poisonous plant of the nightshade family, Datura stramonium.
2 the prickly fruit of this. a thorn in one's flesh (or side) a constant annoyance.
Derivatives:
thornless adj. thornproof adj.
Etymology: OE f. Gmc
Useful english dictionary. 2012.