oni·um | \ ˈō-nē-əm 
\
\Definition of onium
(Entry 1 of 2)
: being or characterized by a usually complex cation
-onium
noun suffixDefinition of -onium (Entry 2 of 2)
: an ion having a positive charge
hydronium — compare -ium sense 1b
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More Definitions for onium
onium
adjectiveoni·um | \ ˈō-nē-əm \
\Medical Definition of onium
: being or characterized by a usually complex cation
onium salts
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Time Traveler for onium
The first known use of onium was in 1905
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