ammonium
noun
am·mo·ni·um
ə-ˈmō-nē-əm 
: an ion NH4+ derived from ammonia by combination with a hydrogen ion and known in compounds (such as salts) that resemble in properties the compounds of the alkali metals
Examples of ammonium in a Sentence
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Those materials include sodium perchlorate, ammonium perchlorate precursors and nitrocellulose, all key components in solid-fuel rocket motors.
—
Antonio María Delgado, Miami Herald, 30 Dec. 2025
Although water board inspectors originally found high levels of ammonium-nitrate and phosphorus at the egg ranch, later tests found almost no contaminants after egg wash wastewater was put into temporary holding tanks and hauled offsite.
—Regina Elling, San Diego Union-Tribune, 30 Dec. 2025
The second is ammonium metatungstate, a cluster of tungsten and oxygen atoms that can accept and hold multiple electrons, much like a tiny rechargeable battery.
—Rupendra Brahambhatt, Interesting Engineering, 27 Dec. 2025
Most disinfectant wipes contain ammonium compounds and some kind of alcohol for killing bacteria and viruses.
—Brandee Gruener, Southern Living, 11 Nov. 2025
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Antonio María Delgado, Miami Herald, 30 Dec. 2025
Although water board inspectors originally found high levels of ammonium-nitrate and phosphorus at the egg ranch, later tests found almost no contaminants after egg wash wastewater was put into temporary holding tanks and hauled offsite.
—Regina Elling, San Diego Union-Tribune, 30 Dec. 2025
The second is ammonium metatungstate, a cluster of tungsten and oxygen atoms that can accept and hold multiple electrons, much like a tiny rechargeable battery.
—Rupendra Brahambhatt, Interesting Engineering, 27 Dec. 2025
Most disinfectant wipes contain ammonium compounds and some kind of alcohol for killing bacteria and viruses.
—Brandee Gruener, Southern Living, 11 Nov. 2025
See All Example Sentences for ammonium
Cite this Entry
“Ammonium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ammonium. Accessed 11 Jan. 2026.
Copy CitationKids Definition
ammonium
noun
am·mo·ni·um
ə-ˈmō-nē-əm
: an ion that comes from the combination of ammonia with a hydrogen ion
Medical Definition
ammonium
noun
am·mo·ni·um
ə-ˈmō-nē-əm
: an ion NH4+ derived from ammonia by combination with a hydrogen ion and known in organic compounds (as quaternary ammonium compounds) and in compounds (as salts) that resemble in properties the compounds of the alkali metals
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