peritoneum

/ˌpɛ.ɹɪ.təˈniː.əm/

//ˌpɛ.ɹɪ.təˈniː.əm// noun

"peritoneum" is a 10-letter English headword indexed on PlainSpell.

The verdict

“peritoneum” is uncommon English (frequency #81,693 among 4,417 “P” headwords), classed as a noun. The kind of spelling people second-guess.

#81,693
frequency rank, English
4,417
“P” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - In mammals, the serous membrane lining the cavity of the abdomen and that is folded over the viscera.

Corpus desk

Index EN-peritoneum · peritoneum · English

peritoneum · rank #81,693 · 0 variants · 0 confusables

  • FREQ-RARE #81,693
  • LEN-MEGA 10 letters
  • VOW-5 5 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 4,417
  • PHOTO-FINISH perineal

Nearest frequency peer: perineal (-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 “peritoneum”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

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

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for peritoneum
PropertyValue
Headwordperitoneum
LanguageEnglish
Part of speechNoun
IPA/ˌpɛ.ɹɪ.təˈniː.əm/
Letters10
Frequency rank#81,693
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “peritoneum” in English

Word frequency stretches from the small set of words we reach for constantly (left) out to the long tail barely used once in a while (right).peritoneumfalls 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: “perineal” (#81,692), “phablet” (#81,695), “penitential” (#81,690). Among 4,417 “P” headwords, “peritoneum” is #81,693. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

peritoneum is uncommon English at frequency #81,693 among 4,417 “P” headwords, classed as anoun, transcribed /ˌpɛ.ɹɪ.təˈniː.əm/. Rarity is why readers land here mid-draft. 2 senses are on record.

peritoneum doesn't appear in our generated misspelling index, a straightforward case of a spelling with little room for common typos. This entry stands alone in our confusable dataset, which typically means the spelling is too distinctive to be mistaken for another word.

Etymologically, the entry records: From Latin peritonaeum, from Ancient Greek περιτόναιον (peritónaion), from περιτόναιος (peritónaios, “stretched or strained over”). The correct English form is peritoneum, spelled P-E-R-I-T-O-N-E-U-M.

Definition

  1. 1
    In mammals, the serous membrane lining the cavity of the abdomen and that is folded over the viscera.
  2. 2
    In animals, the membrane lining the coelom cavity.

Etymology

From Latin peritonaeum, from Ancient Greek περιτόναιον (peritónaion), from περιτόναιος (peritónaios, “stretched or strained over”).

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 "peritoneum"?
"peritoneum" is spelled P-E-R-I-T-O-N-E-U-M. The IPA pronunciation is /ˌpɛ.ɹɪ.təˈniː.əm/.
What does "peritoneum" mean?
As a noun, "peritoneum" means: In mammals, the serous membrane lining the cavity of the abdomen and that is folded over the viscera.
How do you pronounce "peritoneum"?
The IPA (International Phonetic Alphabet) transcription for "peritoneum" is /ˌpɛ.ɹɪ.təˈniː.əm/. 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 "peritoneum"?
From Latin peritonaeum, from Ancient Greek περιτόναιον (peritónaion), from περιτόναιος (peritónaios, “stretched or strained over”). 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 "peritoneum", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 10 letters (nearest by frequency rank).

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

Source: FrequencyWords open word-frequency list