lixivial adjective1 •(no longer used) Of or derived from lye or wood ashes.But such may rest satisfied that those dextrous and conscientious Artificers the Chymists, can furnish us with a Lixival Salt of any Plant we want, made from the Cineres Clavellati or Pot-Ashes. — 1752 formsmore lixivial · most lixivial