Ium definition
Chemical element or group.
Californium.
suffix
Used to indicate the setting where a given activity is carried out: gymnasium, auditorium, stadium, colloquium, planetarium, podium, sanatorium. Words so formed often take "-a" for the plural.
suffix
Forming the names of certain biological structures.
Conidium, syncytium.
affix
Forming Modern Latin names for chemical elements.
Sodium.
affix
Forming the names of certain positive ions.
Ammonium, carbonium.
affix
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By extension, appended to common words to create scientific-sounding or humorous-sounding fictional substance names.
suffix
Origin of ium
- ModL < L, ending of certain neuter nouns
From Webster's New World College Dictionary, 5th Edition
- New Latin -ium neuter n. suff. from Greek -ion
From American Heritage Dictionary of the English Language, 5th Edition
- From Latin -um (“neuter singular morphological suffix”), based on Latin terms for metals, such as ferrum.
From Wiktionary