v. [UN-2 6.]
1. a. trans. To take out of a doubled or folded state; to straighten out. b. intr. To become unfolded or straight.
1611. Florio, Sdoppiare, to vndouble, to vnfold.
1683. Moxon, Mech. Exerc., Printing, xxiv. ¶ 15. As he comes to a Token-sheet, he un-doubles that, and smooths out the Crease.
1730. A. Gordon, Maffai’s Amphith., 363. Then undoubling the Rope,… I extended the Rope with a Pin.
1843. Rufus Dawes, Boyhood Memories, in Boston Misc., III. 61/1. ‘Don’t hit me again on the ear!’ shrieks Bangs, shaking his head at the master, and doubling up his fists under the form. But a few more whacks undoubles them again, and reduces him to a sullen obedience.
1850. Thackeray, Pendennis, lviii. The dirty fist … was obliged to undouble itself.
1889. Advance (Chicago), 14 Nov. To Jim’s surprise, the fists undoubled, and no angry words came.
2. Chess. To move (pawns) so that one no longer stands directly in front of the other.
1868. Illustr. Lond. News, 25 Aug., 187. By this advance Dr. Lange undoubles and consolidates the Pawns on the Q’s side, and thus adds greatly to the strength of his game.
