exostosis

noun

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

The verdict

“exostosis” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.

Unranked
below top-frequency English
9
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A benign, bony growth, often covered with cartilage, on the surface of a bone or tooth.

Corpus desk

Index EN-exostosis · exostosis · English

exostosis · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-LONG 9 letters
  • VOW-4 4 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "E" thin
  • PHOTO-UNK Peer pending

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.

Key facts for exostosis
PropertyValue
Headwordexostosis
LanguageEnglish
Part of speechNoun
Letters9
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “exostosis” in English

exostosissits beyond the 100,000 most-frequent English words, in the long tail of technical, archaic, or otherwise rare vocabulary where spelling doubt tends to strike hardest.

Beyond rank #100,000. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

exostosis is uncommon English outside the top frequency list, classed as anoun. Rarity is why readers land here mid-draft. Gloss: "A benign, bony growth, often covered with cartilage, on the surface of a bone or tooth.".

We couldn't generate a plausible misspelling set for exostosis, and the word's spelling is regular enough that our generator found nothing worth flagging. No confusable counterpart is on file for this word, suggesting its spelling stands apart enough that readers rarely confuse it with something else.

Etymologically, the entry records: From Koine Greek ἐξόστωσις (exóstōsis, “diseased excrescence on the bone”), from Ancient Greek ὀστέον (ostéon, “bone”). The correct English form is exostosis, spelled E-X-O-S-T-O-S-I-S.

Definition

  1. 1
    A benign, bony growth, often covered with cartilage, on the surface of a bone or tooth.

Recorded use

Wiktionary examples

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

  1. Unquestionably, gentlemen, the bones most liable to exostosis are, first, the femur; secondly, the humeri; and thirdly, the lower jaw. But exostoses are met with on the sternum clavicle, and the bones of the head; in short, I may state, that there are no bones on which exostoses may not be produced.
  2. Exostoses are the most common benign tumors of the EAC.^([External Auditory Canal])

Etymology

From Koine Greek ἐξόστωσις (exóstōsis, “diseased excrescence on the bone”), from Ancient Greek ὀστέον (ostéon, “bone”).

Synonyms

bone spur

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). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "exostosis"?
"exostosis" is spelled E-X-O-S-T-O-S-I-S.
What does "exostosis" mean?
As a noun, "exostosis" means: A benign, bony growth, often covered with cartilage, on the surface of a bone or tooth.
What is the origin of the word "exostosis"?
From Koine Greek ἐξόστωσις (exóstōsis, “diseased excrescence on the bone”), from Ancient Greek ὀστέον (ostéon, “bone”). 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.

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

Source: FrequencyWords open word-frequency list