unhelp

From Middle English unhelpen, equivalent to un- +‎ help.

unhelp (third-person singular simple present unhelps, present participle unhelping, simple past unholp or unhelped, past participle unholpen or unhelped)

1. (transitive) To undo or impede the help of.
   • 2000, Mary Ann Froehlich, Peggysue Wells, What to Do When You Don't Know What to Say:

     When I was a child, I remember my mom busily preparing for a dinner party, saying, "If you are not going to help me, then at least don't unhelp me."

   • 2004, Alejna Brugos, Linnea Micciulla, Christine E. Smith, Proceedings of the 28th Annual Boston University Conference on Language Development, Volume 2:

     "No more help! I want you to unhelp me."

From Middle English unhelpe, equivalent to un- +‎ help.

unhelp (uncountable)

1. Lack or absence of help
   • 1950, Frank Kendon, Jacob & Thomas: Darkness, page 18:

     But the unhelp, the disobedience!

• unhelpfulness