-ium

From Latin -um (“neuter singular morphological suffix”), based on Latin terms for metals such as ferrum (“iron”).

-ium

1. (chemistry) Used to form the names of metal elements, after the style of early-named elements, as well as the isotopes of hydrogen.
2. (chemistry) Used to form the temporary systematic element name of a metallic or nonmetallic element which is postulated to exist, or which has been newly synthesized and has not yet been assigned a permanent name.
3. (chemistry) Used to form the name of polyatomic cations.
4. (by extension, humorous) Appended to common words to create scientific-sounding or humorous-sounding fictional substance names.
   • 1997, Bryan Pfaffenberger, Official Microsoft Internet Explorer 4 book, page 34:

     According to the FAQ, a site's coolness can be attributed to a trace element called coolium.

   • 2007, Jason Lethcoe, Wishing Well, appendix, page ii:

     Stupidium: Exposure to this Element can cause very silly behavior.

   • 2009, Selena Kitt, Quickies, page 91:

     We're at the North Pole, aren't we? Let's just call the new element Santa Clausium!

Reanalysis from multiple Latin or New Latin compounds suffixed with -ium, whose function, among others, is to derive parasynthetic compounds.

-ium (plural -iums, irregular plural -ia)

1. Used to form the name of an aggregation or mass of something, such as biological tissue

   epithelium, pollinium

Reanalysis of Latin words suffixed with -tōrium, -ārium and -ium.

-ium (plural -iums, irregular plual -ia)

1. Used to indicate the setting where a given activity is carried out

   auditorium, gymnasium, planetarium

Reanalysis of ammonium or from -onium of the same source.

-ium

1. (pharmacology) Used to form names of quaternary ammonium compounds used as neuromuscular blocking agents, cholinergic agents, anticholinergic agents, antibacterials/antiseptics, or other agents.

   Alternative form: -onium

• (Etymology 1) -um
• -ion

• IMU, MUI, Miu, Mui, UIM, imu

-ium

1. -ium

From -ius (suffix forming adjectives): as a nominal suffix (Suffix 1), a substantivisation of its neuter forms; as an adjectival suffix (Suffix 2), regularly declined forms. Compare Ancient Greek -ιον (-ion), Proto-Slavic *-ьje.

• (Classical) IPA^(key): /i.um/, [iʊ̃ˑ]
• (modern Italianate Ecclesiastical) IPA^(key): /i.um/, [ium] (stressed on the antepenult)

-ium n (genitive -iī or -ī); second declension

1. Suffix used to form abstract nouns, sometimes denoting offices and groups. May no longer be productive.

   ‎auspex + ‎-ium → ‎auspicium

   ‎dēsīderō + ‎-ium → ‎dēsīderium

   ‎castellum (“castle”) + ‎-ium → ‎castilium (“fortified city”)

2. (New Latin) Suffix appended to form names of chemical elements.

Second-declension noun (neuter).

¹Found in older Latin (until the Augustan Age).

• Norwegian Bokmål: -ium

See the etymology of the corresponding lemma form.

-ium

1. inflection of -ius:
   1. nominative/accusative/vocative neuter singular
   2. accusative masculine singular

See the etymology of the corresponding lemma form.

-ium

1. genitive plural of -s

• “-ium” on page 981/3 of the Oxford Latin Dictionary (1st ed., 1968–82)

From Latin -ium (forms names of chemical elements), from -ius (forms adjectives), from Old Latin -iōs, from Proto-Italic *-jos (forms comparative adverbs), from Proto-Indo-European *-yōs ~ *-is- (forms adjectives).

• IPA^(key): /ɪ.ʉm/

• Audio

  (file)

• Rhymes: -ʉm
• Hyphenation: -i‧um

-ium

1. Used to form nouns (loanwords) of Greek or Latin origin; -ium

   akvarium, evangelium, kriterium, kollegium, laboratorium, medium, privilegium, sanatorium, studium ― aquarium, gospel, criterion, college, laboratory, medium, privilege, sanatorium, study

2. (chemistry) Used to form nouns denoting chemical compounds, especially elements; -ium

   barium, aluminium, beryllium, ammonium ― barium, aluminium, beryllium, ammonium

3. (botany) Used to form nouns denoting plant designations; -ium

   geranium ― geranium

4. (geology) Used to form nouns denoting geological designations; -ium

   alluvium, kambrium, ordovicium ― alluvium, cambrium, ordovicium

• “-ium” in Det Norske Akademis ordbok (NAOB).