If something shrivels, it does not only get smaller. It dries, and its surface pulls into lines — a grape turning into a raisin, a leaf left in the sun, fruit going past its best. You can also shrivel something: heat shrivels the petals. It is more of a picture than shrink. A sweater can shrink in the wash and still look smooth; shrivel almost always brings dryness and wrinkles with it. People use it about the body too, kindly or not: old hands, skin without water. And they stretch it for feelings: a sharp remark can make someone's courage shrivel. That is still the same idea — something living collapsing in on itself. It is ordinary English, a little vivid, fine in speech and writing. After it has happened, British spelling is usually shrivelled (two l's); American spelling often uses one l.