If someone or something is shriveled or shrunken with age, it is withered. If your skin is looking a little withered from being out in the sun all the time, it's time for a really good moisturizer.
The adjective withered is also used to describe vegetation that has dried up or shriveled from loss of moisture. If you've ever seen a raisin, you can picture exactly what happens when a grape becomes withered — it becomes shrunken and wrinkled. Withered is from the word wither, which etymologists suggest is a variant of weather from the same Old English word weder.