The definition of hydronium ion is a hydrogen ion combined with water.
An example of hydronium ion is H30+.
See hydronium ion in Webster's New World College Dictionary
noun
Origin: hydr(o)- + -onium
Also Mentioned In
hydrogen ion
Browse entries near hydronium ion
hydrometeor
hydrometer
hydromorphic
hydronaut
hydronic
hydronium
hydropathy
hydrophane
hydrophilic
hydrophilous