ruthenium

/ɹuːˈθiːniəm/

//ɹuːˈθiːniəm// noun

"ruthenium" is a 9-letter English headword indexed on PlainSpell.

The verdict

“ruthenium” is uncommon English (frequency #79,030 among 3,094 “R” headwords), classed as a noun. The kind of spelling people second-guess.

#79,030
frequency rank, English
3,094
“R” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A metallic chemical element (symbol Ru) with an atomic number of 44.

Corpus desk

Index EN-ruthenium · ruthenium · English

ruthenium · rank #79,030 · 0 variants · 0 confusables

  • FREQ-RARE #79,030
  • LEN-LONG 9 letters
  • VOW-4 4 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 3,094
  • PHOTO-FINISH Sachiko

Nearest frequency peer: Sachiko (+3 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 “ruthenium”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

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

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for ruthenium
PropertyValue
Headwordruthenium
LanguageEnglish
Part of speechNoun
IPA/ɹuːˈθiːniəm/
Letters9
Frequency rank#79,030
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “ruthenium” 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).rutheniumfalls 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: “Sachiko” (#79,033), “Ruislip” (#79,026), “sallow” (#79,035). Among 3,094 “R” headwords, “ruthenium” is #79,030. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

ruthenium is uncommon English at frequency #79,030 among 3,094 “R” headwords, classed as anoun, transcribed /ɹuːˈθiːniəm/. Rarity is why readers land here mid-draft. 2 senses are on record.

ruthenium has no tracked misspelling variants, and the word's spelling is regular enough that our generator found nothing worth flagging. It is not paired with a close-neighbour confusable in our dataset, since nothing in our dataset looks or sounds close enough to cause mix-ups.

Etymologically, the entry records: Ruthenia + -ium. Named by Baltic German scientist Karl Ernst Claus in 1844 in honour of Russia (using the Latin name Ruthenia). The correct English form is ruthenium, spelled R-U-T-H-E-N-I-U-M.

Definition

  1. 1
    A metallic chemical element (symbol Ru) with an atomic number of 44.
  2. 2
    An atom of this element.

Recorded use

Wiktionary examples

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

  1. Their latest catalyst includes some ruthenium.
  2. This reaction substitutes a ruthenium for an osmium.

Etymology

Ruthenia + -ium. Named by Baltic German scientist Karl Ernst Claus in 1844 in honour of Russia (using the Latin name Ruthenia).

This word in other languages

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 "ruthenium"?
"ruthenium" is spelled R-U-T-H-E-N-I-U-M. The IPA pronunciation is /ɹuːˈθiːniəm/.
What does "ruthenium" mean?
As a noun, "ruthenium" means: A metallic chemical element (symbol Ru) with an atomic number of 44.
How do you pronounce "ruthenium"?
The IPA (International Phonetic Alphabet) transcription for "ruthenium" is /ɹuːˈθiːniəm/. 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 "ruthenium"?
Ruthenia + -ium. Named by Baltic German scientist Karl Ernst Claus in 1844 in honour of Russia (using the Latin name Ruthenia). 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 "ruthenium", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 9 letters (nearest by frequency rank).

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

Source: FrequencyWords open word-frequency list