Descriptive:
* The rose's velvety petals hid a sharp thorn beneath its beauty.
* The thorn pierced his finger, leaving a small but painful wound.
* The old, gnarled tree was covered in a thick tangle of thorns.
Figurative:
* His words were like thorns, pricking her heart with their harshness.
* The relationship was riddled with thorns, making it difficult to find happiness.
* Success was a thorn in her side, reminding her of all she had lost.
Contextual:
* The gardener carefully pruned the thorns from the rose bush.
* He used a pair of pliers to remove the thorn from his dog's paw.
* The thorn on the cactus served as a defense mechanism.
The best sentence for "thorn" will depend on the specific context and the desired tone.