hyperpyrexia

noun

"hyperpyrexia" is a 12-letter English headword indexed on PlainSpell.

The verdict

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

Unranked
below top-frequency English
12
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - An excessive and unusual elevation of set body temperature greater than or equal to 41°C (105.8°F), or extremely high fever.

Corpus desk

Index EN-hyperpyrexia · hyperpyrexia · English

hyperpyrexia · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-MEGA 12 letters
  • VOW-6 6 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "H" 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 hyperpyrexia
PropertyValue
Headwordhyperpyrexia
LanguageEnglish
Part of speechNoun
Letters12
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “hyperpyrexia” in English

hyperpyrexiaranks outside the top 100,000 English headwords, in the long tail of specialist, archaic, or seldom-used vocabulary, exactly the territory where a reader stops mid-sentence to double-check spelling.

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

Rare enough to double-check

hyperpyrexia is uncommon English outside the top frequency list, classed as anoun. Rarity is why readers land here mid-draft. Gloss: "An excessive and unusual elevation of set body temperature greater than or equal to 41°C (105.8°F), or extremely high fever.".

Our edit-distance generator produced no likely misspellings for hyperpyrexia, a straightforward case of a spelling with little room for common typos. This headword has no recorded confusable partner, suggesting its spelling stands apart enough that readers rarely confuse it with something else.

Etymologically, the entry records: From hyper- + pyrexia. The correct English form is hyperpyrexia, spelled H-Y-P-E-R-P-Y-R-E-X-I-A.

Definition

  1. 1
    An excessive and unusual elevation of set body temperature greater than or equal to 41°C (105.8°F), or extremely high fever.

Etymology

From hyper- + pyrexia.

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 "hyperpyrexia"?
"hyperpyrexia" is spelled H-Y-P-E-R-P-Y-R-E-X-I-A.
What does "hyperpyrexia" mean?
As a noun, "hyperpyrexia" means: An excessive and unusual elevation of set body temperature greater than or equal to 41°C (105.8°F), or extremely high fever.
What is the origin of the word "hyperpyrexia"?
From hyper- + pyrexia. 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