lithen

verb2

1. •
   (dialect) To thicken a broth or gravy with a thickening agent (e.g. flour, oatmeal, etc.)
2. •
   (no longer used) To make lithe, soften; to ease, mitigate

   • "[…] I only know that for well-nigh all the stricken he hath lithened the fever, and that he hath recalled to life many an one whom the chirurgeon had given over to the chaplain." — 1914