-onium Definition

ōnēəm
affix
Any of a group of compounds that are isologues of ammonium.
Sulfonium.
Webster's New World
A cation.
Hydronium.
Webster's New World
noun

(chemistry) Any cation derived by the addition of a proton to the hydride of any element of the nitrogen, chalcogen or halogen families.

Wiktionary

(chemistry) Any organic derivative of these compounds.

Wiktionary

(physics) The bound pair of a particle and its antiparticle.

Wiktionary

Other Word Forms of -onium

Noun

Singular:
-onium
Plural:
onia

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