potash

/ˈpɑtæʃ/
noun
  1. A type of salt containing potassium, used mainly as a fertilizer to help plants grow.
    • Potash is one of the three main ingredients in most commercial fertilizers.
    • Farmers spread potash on their fields to improve crop yields.
    • The soil was low in potassium, so the gardener added potash.
  2. Any of several potassium compounds, especially potassium carbonate, used in making soap, glass, and other products.
    • In the past, potash was made by burning wood and collecting the ashes.
    • The factory uses potash to produce high-quality glass.
    • Soap makers often mix potash with fats to create soft soap.