to dry up or wither: to lose the moisture that keeps something alive or flowing, so that it shrivels, hardens, or runs dry
This is the verb for what happens when the water goes out of something. A river or sea can dry up so the bed lies bare, a plant can wither when its roots find no moisture, and the same drying can be felt in a body or a spirit that has lost its strength. One picture stands behind all of these: life and movement depend on moisture, and when the moisture fails, what was green and flowing becomes brittle and still.
The senses below sort the occurrences by what dries out, not by a change in the word itself. Water-courses running dry is the most concrete use, the withering of grass and crops is the most frequent, and the figurative drying of a person, a limb, or a hope grows naturally out of the plant image. Hebrew often uses the same verb for the cause and the result: the sun dries the grass, but God can also be the one who dries up the sea, so the action ranges from a slow seasonal fading to a sudden act of power.
Because withering is so visible and final, the prophets reach for this verb again and again to picture judgment. A nation, a vine, or a strong arm that dries up is one whose life has been cut off at the source.