1. To scorch or parch with thirst; to deprive utterly of water; to consume.
2. To become dry; to be deprived utterly of water; to shrivel from lack of water.
3. To scorch or parch with thirst; to deprive utterly of water; to consume.
4. When the amount or supply of something gets smaller and then disappears completely, it dries up.

When something dries up or something dries it up, all the water or other liquid in it goes away.