undouble
un·dou·ble
(ŭn-dŭb′əl)tr.v. un·dou·bled, un·dou·bling, un·dou·bles
To unfold, as a piece of paper money.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
undouble
(ʌnˈdʌbəl)vb (tr)
to stretch out or unfold
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014