unthicken

verb2

1. •
   To make less thick.

   • Ricouer's theory helps unthicken the images in these ancient texts, and there's a way in which this “unthickening” can be seen as exactly the work of the university. — 2004
2. •
   To become less thick.

   • The darkness unthickens and a blowsy moon appears at the window. — 2020