Definitions

1. noun

A positively charged ion of ammonia or a compound containing ammonium (such as ammonium hydroxide or ammonium carbonate)

“The fertilizer contained ammonium sulfate as a nitrogen-rich ingredient.”

2. chemistry

A general term for a positively charged ion of ammonia or ammonium compounds

“In the chemical formula for ammonium chloride (NH4Cl), ‘ammonium’ indicates the ammonium ion (NH4+).”

3. chemistry

A type of salt formed when ammonia reacts with a strong acid

“Ammonium nitrate (NH4NO3) is a type of salt commonly used as a fertilizer.”