Home›Browse›A›ammonium hydroxideammonium hydroxideOur editors are putting together more complete content — check back in about 20 minutesammonium hydroxideammonium hydroxide — nounnoun1. a solution of ammonia in water, used as a cleaning agent.1.nounDefinitiona solution of ammonia in water, used as a cleaning agent.ExampleAmmonium hydroxide is often used in household cleaners.