appendix
/əˈpɛn.dɪks/
"appendix" is a 8-letter English headword indexed on PlainSpell.
The verdict
“appendix” is a moderately-common English word, ranked #14,692 in English word frequency and used as a noun.
- #14,692
- frequency rank, English
- 8
- letters
- 10
- tracked misspellings
- 1
- confusable pair
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Something attached to something else; an attachment or accompaniment.
Visual similarity to commonly confused words
How many letter changes separate each confused pair (Levenshtein distance, normalized).
Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).
| Property | Value |
|---|---|
| Headword | appendix |
| Language | English |
| Part of speech | Noun |
| IPA | /əˈpɛn.dɪks/ |
| Letters | 8 |
| Frequency rank | #14,692 |
| Misspellings tracked | 10 |
| Confusable pairs | 1 |
| Source | Wiktionary (kaikki.org) |
Where “appendix” sits in English frequency
Spelling & Dictionary Insight
The English entry for appendix is 8 letters long, classified as a noun, and transcribed in the International Phonetic Alphabet as /əˈpɛn.dɪks/. Corpus data places it at rank #14,692 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 4 distinct senses for this headword, so context determines which meaning a reader should apply.
Our generated misspelling index lists 10 likely wrong-spelling variants for appendix, with forms such as "apendix", "apepndix", and "appednix". Every one of these variants traces to a single-character edit -- an added or dropped letter, a swapped consonant, or a vowel swap -- the kind of slip a spell-checker is built to catch. It also participates in 1 confusable-pair relationship, "append", where similar look or sound leads writers to substitute one word for another in context.
Etymologically, the entry records: Borrowed from Latin appendix. The correct English form is appendix, spelled A-P-P-E-N-D-I-X.
Definition
- 1Something attached to something else; an attachment or accompaniment.
- 2A text added to the end of a book or an article, containing additional information.
- 3The vermiform appendix.
- 4Any process, prolongation, or projection.
Etymology
Borrowed from Latin appendix.
This word in other languages
Common misspellings
Also misspelled as: apendix,apepndix,appednix,appenddix,appendixx,appendxi,appenidx,appenndix,appnedix,papendix
Misspelling Pattern Breakdown
How far each generated variant is from the correct spelling of appendix - measured in single-character edits (insert, delete, or substitute a letter). Larger bars are easier to catch; one-edit slips are the sneakiest.
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 “appendix”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is A-P-P-E-N-D-I-X - every other letter order is a misspelling in standard orthography.
- Say it as /əˈpɛn.dɪks/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Don't mix it up with “append” - see the side-by-side comparison. appendix vs append
- Browse more English words and confusable pairs in the same reference. English words
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.