unfret

verb3

1. •
   To sooth or calm; to make or become less fretful or stressed.

   • "She'll be all right," Madge assured him. "Now you go out a while, and unfret yourself. It's a boy you've got." — 1936
2. •
   To remove (a string) from the frets of a musical instrument.

   • To avoid confusion, a 0 appears if, as is usually the case, the string is to be unfretted — 2011
3. •
   To smooth after being fretted.

   • My mind misgives: to Joppa will I fly, And for a while to Tharsus shape my course, Until the Lord unfret his angry brows. — 1590