Wiktionary
shrink up
vb. (context intransitive English) To contract or shrink completely; shrivel up.
Usage examples of "shrink up".
We got the company shrink up there now, and a specialist in self-termination is on the way.
Lose your hair, muscles shrink up, you get wrinkly and bony, and then you die of a heart attack, or pneumonia .
Crawl inside and shrink up small and the ship will go away, and no one will trouble you ever again.
Why did It shrink up into a withered, apparently lifeless little homunculus, while its fellow twin, Brutus Hellman, attained to a normal manhood?
I stayed in bed and prayed just to vanish, just to shrink up inward till--by evening when he'd climb our steps --there'd be our stale sheets and my folded clothes but no trace or recollection of me.