forthink

verb5

1. •
   (no longer used) To cause distress or regret to; cause to regret or repent; to vex.
2. •
   [with oneself] (no longer used) To regret; repent.
3. •
   (no longer used) To regret.
4. •
   (no longer used) To repent, be sorry for.
5. •
   (no longer used) To change one's mind about; to renounce.

   • Then gan he thinke, perforce with sword and targe / Her forth to fetch, and Proteus to constraine; / But soone he gan such folly to forthinke againe. — 1596