cerium

See also: cérium

English

Chemical element
Ce
Previous: lanthanum (La)
Next: praseodymium (Pr)

a specimen of cerium, under argon to keep it from oxidizing

Alternative forms

• cererium (a name proposed (but not accepted) to indicate "cerium" does not come from the Greek word for "wax")

Etymology

From Ceres (“a recently discovered asteroid”) +‎ -ium.

Pronunciation

• enPR: sîr'ēəm, IPA^(key): /ˈsɪəɹiəm/

• Audio (Southern England):

  (file)

• Audio (General American):

  (file)

• Rhymes: -ɪəɹiəm

Noun

cerium (usually uncountable, plural ceriums)

2. A chemical element (symbol Ce) with an atomic number of 58, a very soft, ductile, silvery-white metal that tarnishes when exposed to air.
   • 2025 July 18, Timothy McLaughlin, “A Rebel Army Is Building a Rare-Earth Empire on China's Border. The Kachin Independence Organization fought for decades in obscurity. Now it's supplying essential minerals to manufacturers around the world”, in Bloomberg Businessweek‎^[1], archived from the original on 18 July 2025:

     Despite their name, rare earths are not so rare. The most common, cerium, is as plentiful in the Earth's crust as copper or lead. The difference between them and more familiar materials is that, in nature, rare earths are almost never found on their own. Rather, they're mixed with other minerals, and often at low concentrations, making them difficult to mine economically.

Derived terms

• cerate
• ceriation
• ceric
• ceriferous
• cerine
• cerite
• cerium dioxide
• cerium metals
• cerium oxide
• cerium trichloride
• ceroan
• cerous
• dicerium
• ferrocerium
• noncerium
• organocerium
• radiocerium
• tricerium

Related terms

• Ceres
• ceria

Translations

chemical element

• Afrikaans: serium (af)
• Albanian: cerium (sq)
• Arabic: سِيرْيُوم m (siryum)
• Armenian: ցերիում (hy) (cʻerium)
• Asturian: ceriu (ast) m
• Basque: zerioa
• Belarusian: цэ́рый m (céryj)
• Breton: seriom
• Bulgarian: це́рий m (cérij)
• Catalan: ceri (ca) m
• Chinese:

  Mandarin: 鈰 / 铈 (zh) (shì)

• Cornish: keryum
• Czech: cér m, cer (cs) m
• Danish: cerium (da)
• Dutch: cerium (nl) n
• Esperanto: cerio (eo)
• Estonian: tseerium (et)
• Faroese: serium n
• Finnish: cerium (fi)
• French: cérium (fr) m
• Friulian: ceri
• Galician: cerio (gl) m
• Georgian: ცერიუმი (ceriumi)
• German: Cer (de) n
• Greek: δημήτριο (el) n (dimítrio)
• Hebrew: סריום (seryum)
• Hindi: पुष्कला (puṣkalā)
• Hungarian: cérium (hu)
• Icelandic: serín (is)
• Irish: ceiriam
• Italian: cerio (it) m
• Japanese: セリウム (ja) (seriumu)
• Kashubian: cer
• Kazakh: церий (kk) (serii)
• Khmer: សេរ៉្យូម (seeryuum)
• Korean: 세륨 (ko) (seryum)
• Latin: cerium (la)
• Latvian: cērijs
• Lithuanian: ceris (lt)
• Luxembourgish: Zer
• Macedonian: цериум m (cerium)
• Malay: serium
• Maltese: sirjum
• Manx: kerrium
• Mongolian: цери (ceri)
• Norwegian: cerium
• Occitan: cèri m
• Persian: سریم (seriom)
• Polish: cer (pl) m
• Portuguese: cério (pt) m
• Romanian: ceriu (ro) n
• Russian: це́рий (ru) m (cérij)
• Scottish Gaelic: ceiriam
• Serbo-Croatian:

  Cyrillic: церијум m, церијум m

  Roman: cerij (sh) m, cerijum m

• Slovak: cér (sk)
• Slovene: cerij (sl)
• Spanish: cerio (es) m
• Swedish: cerium (sv) n
• Tajik: церий (ceriy)
• Thai: ซีเรียม (sii-rîiam)
• Turkish: seryum (tr)
• Ukrainian: це́рій (uk) m (cérij)
• Uzbek: церий (uz), tseriy
• Vietnamese: xeri
• Volapük: zerin (vo)
• Welsh: ceriwm
• West Frisian: cerium

See also

• allanite
• bastnasite
• CAN
• hydroxylbastnasite
• jeweler's rouge, jeweller's rouge
• monazite
• orthite
• rhabdophane
• synchysite

Anagrams

• uremic

Danish

Chemical element
Ce
Previous: lanthan (La)
Next: praseodym (Pr)

Etymology

From Latin Ceres +‎ -ium.

Noun

cerium n (singular definite ceriummet, not used in plural form)

1. cerium

Declension

Declension of cerium

neuter gender	singular
	indefinite	definite
nominative	cerium	ceriummet
genitive	ceriums	ceriummets

References

• “cerium” in Den Danske Ordbog

Dutch

Chemical element
Ce
Previous: lanthaan (La)
Next: praseodymium (Pr)

Etymology

Borrowed from Swedish cerium, New Latin cerium or French cérium.

Pronunciation

• IPA^(key): /ˈseː.riˌʏm/

• Audio:

  (file)

• Hyphenation: ce‧ri‧um

Noun

cerium n (uncountable, no diminutive)

1. cerium [from 1830s or earlier]

Finnish

Etymology

Internationalism (see English cerium).

Pronunciation

• IPA^(key): /ˈseːri.um/, [ˈs̠e̞ːri.um]
• Rhymes: -eːri.um

Noun

cerium

1. cerium

Declension

Inflection of cerium (Kotus type 5/risti, no gradation)
nominative		cerium	—
genitive		ceriumin	—
partitive		ceriumia	—
illative		ceriumiin	—
		singular	plural
nominative		cerium	—
accusative	nom.	cerium	—
	gen.	ceriumin
genitive		ceriumin	—
partitive		ceriumia	—
inessive		ceriumissa	—
elative		ceriumista	—
illative		ceriumiin	—
adessive		ceriumilla	—
ablative		ceriumilta	—
allative		ceriumille	—
essive		ceriumina	—
translative		ceriumiksi	—
abessive		ceriumitta	—
instructive		—	—
comitative		See the possessive forms below.

Possessive forms of cerium (Kotus type 5/risti, no gradation)

first-person singular possessor singular plural nominative ceriumini — accusative nom. ceriumini — gen. ceriumini genitive ceriumini — partitive ceriumiani — inessive ceriumissani — elative ceriumistani — illative ceriumiini — adessive ceriumillani — ablative ceriumiltani — allative ceriumilleni — essive ceriuminani — translative ceriumikseni — abessive ceriumittani — instructive — — comitative — — second-person singular possessor singular plural nominative ceriumisi — accusative nom. ceriumisi — gen. ceriumisi genitive ceriumisi — partitive ceriumiasi — inessive ceriumissasi — elative ceriumistasi — illative ceriumiisi — adessive ceriumillasi — ablative ceriumiltasi — allative ceriumillesi — essive ceriuminasi — translative ceriumiksesi — abessive ceriumittasi — instructive — — comitative — — first-person plural possessor singular plural nominative ceriumimme — accusative nom. ceriumimme — gen. ceriumimme genitive ceriumimme — partitive ceriumiamme — inessive ceriumissamme — elative ceriumistamme — illative ceriumiimme — adessive ceriumillamme — ablative ceriumiltamme — allative ceriumillemme — essive ceriuminamme — translative ceriumiksemme — abessive ceriumittamme — instructive — — comitative — — second-person plural possessor singular plural nominative ceriuminne — accusative nom. ceriuminne — gen. ceriuminne genitive ceriuminne — partitive ceriumianne — inessive ceriumissanne — elative ceriumistanne — illative ceriumiinne — adessive ceriumillanne — ablative ceriumiltanne — allative ceriumillenne — essive ceriuminanne — translative ceriumiksenne — abessive ceriumittanne — instructive — — comitative — — third-person possessor singular plural nominative ceriuminsa — accusative nom. ceriuminsa — gen. ceriuminsa genitive ceriuminsa — partitive ceriumiaan ceriumiansa — inessive ceriumissaan ceriumissansa — elative ceriumistaan ceriumistansa — illative ceriumiinsa — adessive ceriumillaan ceriumillansa — ablative ceriumiltaan ceriumiltansa — allative ceriumilleen ceriumillensa — essive ceriuminaan ceriuminansa — translative ceriumikseen ceriumiksensa — abessive ceriumittaan ceriumittansa — instructive — — comitative — —

Latin

Etymology 1

From Ancient Greek κηρίον (kēríon).

Pronunciation

• (Classical Latin) IPA^(key): [ˈkeː.ri.ũː]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈt͡ʃɛː.ri.um]

Noun

cērium n (genitive cēriī or cērī); second declension

1. A bad species of swelling or ulcer

Declension

Second-declension noun (neuter).

	singular	plural
nominative	cērium	cēria
genitive	cēriī cērī1	cēriōrum
dative	cēriō	cēriīs
accusative	cērium	cēria
ablative	cēriō	cēriīs
vocative	cērium	cēria

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

Etymology 2

Chemical element
Ce
Previous: lanthanum (La)
Next: praseodymium (Pr)

Pronunciation

• (Classical Latin) IPA^(key): [ˈkɛ.ri.ũː]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈt͡ʃɛː.ri.um]

Noun

cerium n (genitive ceriī); second declension

1. (New Latin) cerium

Declension

Second-declension noun (neuter).

	singular	plural
nominative	cerium	ceria
genitive	ceriī	ceriōrum
dative	ceriō	ceriīs
accusative	cerium	ceria
ablative	ceriō	ceriīs
vocative	cerium	ceria

References

• “cerium”, in Charlton T. Lewis and Charles Short (1879), A Latin Dictionary, Oxford: Clarendon Press
• “cerium”, in Gaffiot, Félix (1934), Dictionnaire illustré latin-français, Hachette.

Swedish

Chemical element
Ce
Previous: lantan (La)
Next: praseodym (Pr)

Noun

cerium n

1. cerium

Declension

Declension of cerium

		nominative	genitive
singular	indefinite	cerium	ceriums
	definite	ceriumet	ceriumets
plural	indefinite	—	—
	definite	—	—

Declension of cerium

		nominative	genitive
singular	indefinite	cerium	ceriums
	definite	ceriet	ceriets
plural	indefinite	—	—
	definite	—	—

Declension of cerium

		nominative	genitive
singular	indefinite	cerium	ceriums
	definite	cerium	ceriums
plural	indefinite	—	—
	definite	—	—

References

• cerium in Svensk ordbok (SO)
• cerium in Svenska Akademiens ordlista (SAOL)
• cerium in Svenska Akademiens ordbok (SAOB)
• Svensk MeSH