nucleus

/ˈnjuː.kli.əs/

//ˈnjuː.kli.əs// noun

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

"nucleus" is a 7-letter English headword indexed on PlainSpell.

The verdict

“nucleus” has 10 generated spelling variants in the English index at frequency #13,203. The variants make it a useful spelling check.

#13,203
frequency rank, English
24,391
“N” headwords
10
tracked misspellings
3
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - The core, central part of something, around which other elements are assembled.

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

nucleus vs nuclei
71% similar
nucleus vs nuclear
71% similar
nucleus vs nucleic
71% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for nucleus
PropertyValue
Headwordnucleus
LanguageEnglish
Part of speechNoun
IPA/ˈnjuː.kli.əs/
Letters7
Frequency rank#13,203
Misspellings tracked10
Confusable pairs3
SourceWiktionary (kaikki.org)

Where “nucleus” sits in English frequency

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

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

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

A misspelling magnet

The generator records 10 spelling variants around nucleus (IPA /ˈnjuː.kli.əs/), anoun. Corpus frequency is #13,203 among 24,391 “N” headwords. Wiktionary lists 7 senses, so context still picks the gloss.

Our generated misspelling index lists 10 likely wrong-spelling variants for nucleus, with forms such as "nculeus", "nnucleus", and "nuccleus". Each variant is a distinct typo pattern an edit-distance generator flags, typically a doubled-consonant error, a silent-letter drop, or a vowel substitution. It also participates in 3 confusable-pair relationships, "nuclei", "nuclear", "nucleic", where similar look or sound leads writers to substitute one word for another in context.

Etymologically, the entry records: Learned borrowing from Latin nucleus (“kernel, core”). The earliest uses refer to the head of a comet and the kernel of a seed, both recorded in Lexicon Technicum in 1704. The sense in atomic physics was coined by British scientist Michael Faraday in 1844 i… The correct English form is nucleus, spelled N-U-C-L-E-U-S.

Definition

  1. 1
    The core, central part of something, around which other elements are assembled.
  2. 2
    An initial part or version that will receive additions.
  3. 3
    The massive, positively charged central part of an atom, made up of protons and neutrons.
  4. 4
    A large membrane-enclosed organelle found in eukaryotic cells which contains genetic material.
  5. 5
    A ganglion, cluster of many neuronal bodies where synapsing occurs.
  6. 6
    The central part of a syllable, most commonly a vowel.
  7. 7
    A small bee-hive used to create a colony from a larger existing one.

Etymology

Learned borrowing from Latin nucleus (“kernel, core”). The earliest uses refer to the head of a comet and the kernel of a seed, both recorded in Lexicon Technicum in 1704. The sense in atomic physics was coined by British scientist Michael Faraday in 1844 in a theoretical meaning.

This word in other languages

núcleo(Español)noyau(Français)Kern(Deutsch)núcleo(Português)

Common misspellings

Also misspelled as:

  • nculeus
  • nnucleus
  • nuccleus
  • nucelus
  • nuclesu
  • nucleuss
  • nuclleus
  • nuclues
  • nulceus
  • uncleus

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of nucleus - measured in single-character edits (insert, delete, or substitute a letter). Larger bars are easier to catch; one-edit slips are the sneakiest.

nculeus2nnucleus1nuccleus1nucelus2nuclesu2nucleuss1nuclleus1nuclues2
Edit distance from "nucleus"

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 "nucleus"?
"nucleus" is spelled N-U-C-L-E-U-S. The IPA pronunciation is /ˈnjuː.kli.əs/.
What does "nucleus" mean?
As a noun, "nucleus" means: The core, central part of something, around which other elements are assembled.
What words are commonly confused with "nucleus"?
"nucleus" is commonly confused with "nuclei", "nuclear", "nucleic". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "nucleus"?
The IPA (International Phonetic Alphabet) transcription for "nucleus" is /ˈnjuː.kli.əs/. 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 "nucleus"?
Learned borrowing from Latin nucleus (“kernel, core”). The earliest uses refer to the head of a comet and the kernel of a seed, both recorded in Lexicon Technicum in 1704. The sense in atomic physics was coined by British scientist Michael Faraday... 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.

Using “nucleus”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is N-U-C-L-E-U-S - every other letter order is a misspelling in standard orthography.
  • Say it as /ˈnjuː.kli.əs/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Don't mix it up with “nuclei” - see the side-by-side comparison. nucleus vs nuclei
  • Browse more English words and confusable pairs in the same reference. English words

Same frequency band

Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

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

Source: FrequencyWords open word-frequency list FrequencyWords open word-frequency list