From Middle English undoinge, undoynge, ondoynge; equivalent to undo + -ing.
undoing (plural undoings)
- The act of loosening or unfastening
- Ruin; defeat, (also) that which causes defeat or ruin.
- His fatal flaw was his undoing. In a sense he defeated himself.
- 1912 October, Edgar Rice Burroughs, “Tarzan of the Apes”, in The All-Story, New York, N.Y.: Frank A. Munsey Co., →OCLC; republished as chapter 5, in Tarzan of the Apes, New York, N.Y.: A. L. Burt Company, 1914, →OCLC:
- So far as the ape was concerned, Sabor reasoned correctly. The little fellow crouched trembling just an instant, but that instant was quite long enough to prove his undoing.
- 2018 July 3, Phil McNulty, “Colombia 1 - 1 England”, in BBC Sport:
- The extra 30 minutes could not separate the sides and led to a nerve-shredding finale that has so often been England's undoing, with a dismal record of just one win in seven shootouts at major tournaments before this.
- Annulment; reversal
that which defeats
From Middle English undoynge, undoand, from Old English undōnde (“undoing”), from Proto-Germanic *andadōndz, present participle of *andadōną (“to undo”). Cognate with Dutch ontdoend (“undoing”).