astigmatism
/əˈstɪɡmətɪzm̩/
"astigmatism" is a 11-letter English headword indexed on PlainSpell.
The verdict
“astigmatism” is uncommon English (frequency #55,927 among 35,202 “A” headwords), classed as a noun. The kind of spelling people second-guess.
- #55,927
- frequency rank, English
- 35,202
- “A” headwords
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - A defect of a lens such that light rays coming from a point do not meet at a focal point so that the image is blurred.
| Property | Value |
|---|---|
| Headword | astigmatism |
| Language | English |
| Part of speech | Noun |
| IPA | /əˈstɪɡmətɪzm̩/ |
| Letters | 11 |
| Frequency rank | #55,927 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “astigmatism” sits in English frequency
Rare enough to double-check
astigmatism is uncommon English at frequency #55,927 among 35,202 “A” headwords, classed as anoun, transcribed /əˈstɪɡmətɪzm̩/. Rarity is why readers land here mid-draft. 2 senses are on record.
The misspelling generator found no plausible variants for astigmatism, a straightforward case of a spelling with little room for common typos. Our dataset records no confusable match here, a sign it's visually distinctive enough not to be mixed up with another word.
Etymologically, the entry records: From a- (negative prefix) + stem of Ancient Greek στίγμα (stígma, “mark, point”) + -ism. Coined by English polymath William Whewell in 1846. The correct English form is astigmatism, spelled A-S-T-I-G-M-A-T-I-S-M.
Definition
- 1A defect of a lens such that light rays coming from a point do not meet at a focal point so that the image is blurred.
- 2A disorder of the vision, usually due to a misshapen cornea, such that light does not focus correctly on the retina causing a blurred image.
Etymology
From a- (negative prefix) + stem of Ancient Greek στίγμα (stígma, “mark, point”) + -ism. Coined by English polymath William Whewell in 1846.
Synonyms
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
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Using “astigmatism”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is A-S-T-I-G-M-A-T-I-S-M - every other letter order is a misspelling in standard orthography.
- Say it as /əˈstɪɡmətɪzm̩/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Browse more English words and confusable pairs in the same reference. English words
Other uncommon English words near this rank
Data Source
Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.