D defs.my
Entry 1 sense Webster, 1913

Ammonium

/əmō'nēəm/ · Am·mo·ni·um · IPA /əˈmoʊni.əm/
01 n. A compound radical, NH4, having the chemical relations of a strongly basic element like the alkali metals.
  1. 1.
    A compound radical, NH4, having the chemical relations of a strongly basic element like the alkali metals.(Chem.)