Definitions

1. noun

an old term for potash, a mixture of potassium carbonate and other potassium salts, often used in medicine or as a fertilizer

“The medieval apothecary added potassa to the potion to enhance its healing properties.”

2. noun

a type of alkaline substance, often used in glassmaking and soap production

“The potassa was essential for the production of high-quality glassware.”