unclap

From un- +‎ clap.

unclap (third-person singular simple present unclaps, present participle unclapping, simple past and past participle unclapped)

1. (transitive) To remove (one's hand clapped over one's mouth, or similar).
   • 2013, Jennifer Echols, Playing Dirty, page 21:

     He unclapped the hand over his mouth to announce, “The PR chick is enormous and scary, with pink hair.”

   • 2016, Darcy Woods, Summer of Supernovas, page 234:

     I slowly nod, afraid to unclap my hand from my mouth, afraid of the words that might spill out: […]