Thorn
Definition 1 of 3
Pro Tip 1/3
Part of Plant
Thorn specifically refers to sharp extensions on plants, not sharp objects in general. Roses and cacti are common plants known for their thorns.
Pro Tip 2/3
Painful Touch
Thorns can prick your skin, so approach with caution when dealing with thorny plants. I accidentally pricked my finger on a thorn while gardening.
Pro Tip 3/3
Natural Defense
Plants have thorns as a defense mechanism to protect from herbivores. The thorns on that bush protect it from being eaten by animals.