headcase

noun

"headcase" is a 8-letter English headword indexed on PlainSpell.

The verdict

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

Unranked
below top-frequency English
8
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A mentally unbalanced, unpredictable person, especially one who displays aggressive behavior.

Corpus desk

Index EN-headcase · headcase · English

headcase · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-LONG 8 letters
  • VOW-4 4 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 headcase
PropertyValue
Headwordheadcase
LanguageEnglish
Part of speechNoun
Letters8
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “headcase” in English

headcasefalls outside the top-100,000 ranked English words, the long-tail zone of technical, archaic, or low-frequency vocabulary, exactly where readers second-guess spellings most.

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

Rare enough to double-check

headcase is uncommon English outside the top frequency list, classed as anoun. Rarity is why readers land here mid-draft. 2 senses are on record.

Our edit-distance generator produced no likely misspellings for headcase, a straightforward case of a spelling with little room for common typos. We don't track a confusable pairing for this entry, suggesting its spelling stands apart enough that readers rarely confuse it with something else.

Etymologically, the entry records: From head + case. The correct English form is headcase, spelled H-E-A-D-C-A-S-E.

Definition

  1. 1
    A mentally unbalanced, unpredictable person, especially one who displays aggressive behavior.
  2. 2
    A genetic sequence that inhibits terminal branching of the trachea and regulates dendrite pruning.

Recorded use

Wiktionary examples

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

  1. "A stockbroker doesn't have 80,000 people sitting behind him just waiting for a mistake," says Jim Fassel, whom fans serenaded with "Fire Fassel!" chants during his final weeks as head coach of the New York Giants last season. "It can drive you crazy." From head coach to head case in three easy steps.
  2. Another gene downstream of EcR/Usp is headcase. Screening genes that show genetic interactions with EcR mutants, Loncle and Williams identified headcase as a regulator of dendrite pruning (Loncle and Williams 2012).

Etymology

From head + case.

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 "headcase"?
"headcase" is spelled H-E-A-D-C-A-S-E.
What does "headcase" mean?
As a noun, "headcase" means: A mentally unbalanced, unpredictable person, especially one who displays aggressive behavior.
What is the origin of the word "headcase"?
From head + case. 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