deharden

de- +‎ harden

deharden (third-person singular simple present dehardens, present participle dehardening, simple past and past participle dehardened)

1. (transitive, intransitive) To make or become less hard (resistant to pressure).
   • 1930, Camera: A Practical Magazine for Photographers, volume 41:

     It is possible by careful adjustment of concentrations to deharden the gelatine and cut down any obnoxious soaking periods to convenient times.

   • 2015 December 19, “Impacts of Climate Change on the Timing of the Production Season of Maple Syrup in Eastern Canada”, in PLOS ONE‎, →DOI:

     Below freezing winter temperatures must last long enough for the tree to begin the dehardening process necessary for the beginning of sap production; should this period become too short, tree physiology and vigor could be affected which would reduce sap production.

• adherend, hardened