alum
/ˈæləm/
noun
- A former student of a particular school, college, or university.
- She is an alum of Harvard University.
- As an alum, he donates to the scholarship fund every year.
- The school invited all its alums to the reunion.
- A chemical compound, a double sulfate of aluminum and another element, used in water purification, dyeing, and cooking.
- In the past, alum was used in some deodorants.
- The recipe calls for a pinch of alum to keep pickles crisp.
- Alum is often added to water to help remove impurities.
Synonyms