cerium

/ˈsɪəɹiəm/

//ˈsɪəɹiəm// noun

By · According to Wiktionary data (CC BY-SA) ·

"cerium" is a 6-letter English headword indexed on PlainSpell.

The verdict

“cerium” is uncommon English (frequency #77,518 among 5,599 “C” headwords), classed as a noun. The kind of spelling people second-guess.

#77,518
frequency rank, English
5,599
“C” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A chemical element (symbol Ce) with an atomic number of 58, a very soft, ductile, silvery-white metal that tarnishes when exposed to air.

Corpus desk

Index EN-cerium · cerium · English

cerium · rank #77,518 · 0 variants · 0 confusables

  • FREQ-RARE #77,518
  • LEN-LONG 6 letters
  • VOW-3 3 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-DENSE 5,599
  • PHOTO-FINISH centroid

Nearest frequency peer: centroid (-1 rank slots)

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Long-tail ranks near “cerium”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

What this shows Long-tail view: where “cerium” sits against similarly uncommon English ranks.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for cerium
PropertyValue
Headwordcerium
LanguageEnglish
Part of speechNoun
IPA/ˈsɪəɹiəm/
Letters6
Frequency rank#77,518
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “cerium” in English

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right).ceriumfalls in this rarity band:

#1#100#1K#10K#100K
← used constantlyrarely used →

The axis is logarithmic, with each marked tick roughly ten times rarer than the last. Rare peers in the same band: “centroid” (#77,517), “Chaves” (#77,521), “chelation” (#77,523). Among 5,599 “C” headwords, “cerium” is #77,518. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

cerium is uncommon English at frequency #77,518 among 5,599 “C” headwords, classed as anoun, transcribed /ˈsɪəɹiəm/. Rarity is why readers land here mid-draft. Gloss: "A chemical element (symbol Ce) with an atomic number of 58, a very soft, ductile, silvery-white metal that tarnishes when exposed to air.".

We couldn't generate a plausible misspelling set for cerium, since its letter sequence doesn't invite the usual edit-distance slips. We don't track a confusable pairing for this entry, since nothing in our dataset looks or sounds close enough to cause mix-ups.

Etymologically, the entry records: From Ceres (“a famous asteroid”) + -ium. The element was discovered and named in 1803. It was named after the asteroid, which had been discovered recently (1801) and had been named after Ceres, the Roman goddess of agriculture. This was during an era when a… The correct English form is cerium, spelled C-E-R-I-U-M.

Definition

  1. 1
    A chemical element (symbol Ce) with an atomic number of 58, a very soft, ductile, silvery-white metal that tarnishes when exposed to air.

Recorded use

Wiktionary example

These source excerpts show how cerium appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. 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 m…

Etymology

From Ceres (“a famous asteroid”) + -ium. The element was discovered and named in 1803. It was named after the asteroid, which had been discovered recently (1801) and had been named after Ceres, the Roman goddess of agriculture. This was during an era when asteroids were culturally exciting things that humans were just beginning to understand properly in astronomical terms, and the era also featured a fascination with neoclassical themes and thus naming things after icons of ancient Greek and Roman mythology and literature.

This word in other languages

cerio(Español)cérium(Français)Cer(Deutsch)cério(Português)

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "cerium"?
"cerium" is spelled C-E-R-I-U-M. The IPA pronunciation is /ˈsɪəɹiəm/.
What does "cerium" mean?
As a noun, "cerium" means: A chemical element (symbol Ce) with an atomic number of 58, a very soft, ductile, silvery-white metal that tarnishes when exposed to air.
How do you pronounce "cerium"?
The IPA (International Phonetic Alphabet) transcription for "cerium" is /ˈsɪəɹiəm/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "cerium"?
From Ceres (“a famous asteroid”) + -ium. The element was discovered and named in 1803. It was named after the asteroid, which had been discovered recently (1801) and had been named after Ceres, the Roman goddess of agriculture. This was during an ... See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "cerium", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 6 letters (nearest by frequency rank).

Chaves#77,521budged#77,486Crisco#77,571Bethan#77,454

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list