stum /stʌm/verb 3noun 2forms 3 verb3 •(no longer used) To ferment. •(no longer used) To renew (wine etc.) by mixing must with it and raising a new fermentation.We stum our crude wines […]to renew their spirits. — 1696 •(no longer used) To fume, as a cask of liquor, with burning sulphur. noun2 •(no longer used) Unfermented grape juice; must.Let our wines, without mixture of stum, be all fine. — 1620 •(no longer used) Wine revived by new fermentation, resulting from the admixture of must.Drink ev'ry letter on't in stum, And make it brisk champaign become. — 1664 formsstummed · stumming · stums