achromatopsia

/ˈə.kɹɒ.mə.tɒp.siə/

//ˈə.kɹɒ.mə.tɒp.siə// noun

"achromatopsia" is a 13-letter English headword indexed on PlainSpell.

The verdict

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

Unranked
below top-frequency English
13
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Total color blindness; the total inability to distinguish colors due to the absence of cone cells in the eyes.

Corpus desk

Index EN-achromatopsia · achromatopsia · English

achromatopsia · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-MEGA 13 letters
  • VOW-6 6 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "A" 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 achromatopsia
PropertyValue
Headwordachromatopsia
LanguageEnglish
Part of speechNoun
IPA/ˈə.kɹɒ.mə.tɒp.siə/
Letters13
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “achromatopsia” in English

achromatopsiafalls 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

achromatopsia is uncommon English outside the top frequency list, classed as anoun, transcribed /ˈə.kɹɒ.mə.tɒp.siə/. Rarity is why readers land here mid-draft. Gloss: "Total color blindness; the total inability to distinguish colors due to the absence of cone cells in the eyes.".

The misspelling generator found no plausible variants for achromatopsia, typically a sign the spelling maps closely to how the word sounds. No confusable counterpart is on file for this word, which typically means the spelling is too distinctive to be mistaken for another word.

Etymologically, the entry records: From German Achromatopsie, from Ancient Greek ἀχρώματος (akhrṓmatos), from ἀ- (a-, “without”) + χρῶμα (khrôma, “color”), + -opsie. By surface analysis, a- + chromato- + -opsia. The correct English form is achromatopsia, spelled A-C-H-R-O-M-A-T-O-P-S-I-A.

Definition

  1. 1
    Total color blindness; the total inability to distinguish colors due to the absence of cone cells in the eyes.

Etymology

From German Achromatopsie, from Ancient Greek ἀχρώματος (akhrṓmatos), from ἀ- (a-, “without”) + χρῶμα (khrôma, “color”), + -opsie. By surface analysis, a- + chromato- + -opsia.

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 "achromatopsia"?
"achromatopsia" is spelled A-C-H-R-O-M-A-T-O-P-S-I-A. The IPA pronunciation is /ˈə.kɹɒ.mə.tɒp.siə/.
What does "achromatopsia" mean?
As a noun, "achromatopsia" means: Total color blindness; the total inability to distinguish colors due to the absence of cone cells in the eyes.
How do you pronounce "achromatopsia"?
The IPA (International Phonetic Alphabet) transcription for "achromatopsia" is /ˈə.kɹɒ.mə.tɒp.siə/. 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 "achromatopsia"?
From German Achromatopsie, from Ancient Greek ἀχρώματος (akhrṓmatos), from ἀ- (a-, “without”) + χρῶμα (khrôma, “color”), + -opsie. By surface analysis, a- + chromato- + -opsia. 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