unstarch

From un- +‎ starch.

unstarch (third-person singular simple present unstarches, present participle unstarching, simple past and past participle unstarched)

1. (transitive) To remove starch from
2. (transitive) to make limp, weak, soft or pliable.

• “unstarch”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.