wart

2. A small hard growth on the skin of an animal, such as a toad.

The toad's back was covered in warts.

3. A small hard lump on the surface of a plant, such as a potato.

She cut the warts off the potato before cooking it.

4. A fault or flaw in a person's character.

Patience was never his strong point, but it was a wart he learned to live with.