From Longman Dictionary of Contemporary Englishuncurlun‧curl /ʌnˈkɜːl $ -ˈkɜːrl/ verb [intransitive, transitive] BEND#to stretch out straight from a curled position, or to make something do this→ See Verb table
Examples from the Corpus
uncurl• His fingers were beginning to uncurl, his own weight dragging him down.• Now suddenly she could feel the pleasure such imaginings had aroused uncurling in a warm spiral in the pit of her stomach.• After a few minutes it will slowly and cautiously uncurl itself again.• As with waiting for a hedgehog to uncurl, prodding didn't help.• I watched the two handsome flags uncurl to the warm wind, then went on my own tour of inspection. 