the monovalent radical NH, present in salts produced by the reaction of ammonia with an acid: its compounds are like those of the alkali metals
Origin of ammoniumModL, coined by Berzelius ; from ammonia + -ium
The univalent chemical ion NH4+, derived from ammonia, whose compounds chemically resemble the alkali metals.
Origin of ammoniumammon(ia) + –ium.
(usually uncountable, plural ammoniums)
ammonia + -ium