Emily Dickinson Lexicon

thorn (-s), n. [OE þorn, thorn.]

1. Point; sharp outgrowth; small goad on a plant stem.
2. Burr; nettle; thistle; [fig.] source of suffering; cause of shame.
3. Spur; prickle; [fig.] hurt; injury; agony; anguish.
4. Bramble; spine; [metonymy] spiked wreath similar to the one that enemies placed on the head of Jesus to mock him (see Matthew 27:29); [metaphor] wound; bruise; [fig.] affliction; trial; trouble.