What’s the plural of “appendix”?
Appendixes is the plural of appendix when referring to anatomy. Appendices is plural in reference to a book or document.
The surgeon removed two inflamed appendixes this morning.
The textbook contained three helpful appendices at the back.
The research paper had six lengthy appendixes.
Many people have their appendices removed if they become infected.
Appendix is a homophone in English, which are words that have more than one meaning though they share the same pronunciation and spelling.
What’s the singular of appendix?
The singular of appendix in either context is appendix.
What does the word appendix mean?
Appendix when referring to anatomy (or an appendage) is defined as “a tube-shaped sac attached to and opening into the lower end of the large intestine in humans and some other mammals.”
As part of a book, an appendix is understood as “a section or table of additional matter at the end of a book or document.” In this sense, an appendix is similar in meaning to an addendum or epilogue.
Other irregular plural nouns (ix– and –ces/-xes suffixes)
Appendix is irregular (does not end in -s or -es) and belongs to the Latin group of irregular nouns. Appendix, and other similarly Latin irregular plurals each converts from its singular –ix or –ex to –xes or –ces as a plural noun.
| singular | plural |
|---|---|
| index | indexes and indices |
| matrix | matrices and matrixes |
| appendix | appendices or appendexes |
| codex | codices or codexes |
| vortex | vortices or vortexes |
| vertex | vertices or vertexes |
| apex | apices or apexes |
Associate ‘appendices’ with ‘indices’ or ‘references’ found in books/documents. ‘Appendixes’ is the plural for the anatomical part.
“Appendix”, used in sentences
- We rushed him to the hospital when we realized that his appendix had ruptured.
1. Cincinnati Bengals 37, Pittsburgh Steelers 30 · Minkah Fitzpatrick started at free safety for the Steelers, eight days after having his appendix removed. Mark Inabinett | Minabinett@al.com, al, 21 Nov. 2022
2. The book’s appendix includes a bibliography.
3. The appendix is the old propane tank in the corner of the basement to the soul. Talia Argondezzi, The New Yorker, 12 Nov. 2022
4. The appendix in the report breaks down the grant recipients. Peter Greene, Forbes, 4 Oct. 2022
“Appendices” / “appendixes”, used in sentences
1. The book has several appendixes.
2. Joly adds valuable notes and thirteen important appendices.
3. They are accompanied by ample annotations and appendices, with illustrations of great merit and value.
4. In many ways the heart of his argument is found not in the text but in the almost algebraic appendices
5. These word limits include notes and appendices, but exclude bibliography.
Synonyms for appendix
- supplement
- addendum
- epilogue
- afterward
- addition
Origin of the word appendix
From etymology online on appendix (n.):
From Latin appendix “an addition, continuation, something attached,” from appendere “cause to hang (from something)”.
What’s the difference between they’re, their, and there?
Work Sheet
According to the post, what is the correct plural of “appendix” when referring to anatomy?
Based on the post, what is the correct plural of “appendix” when referring to a book or document part?
What is the singular form of “appendix” in either context?
Which sentence uses the correct plural form for the anatomical meaning of “appendix” as described in the post?
According to the rule stated in the post, which sentence correctly uses the plural form for the book/document meaning of “appendix”?
The doctor examined the inflamed of the patient.
The historical document included several useful at the end.
He had his removed last year due to infection.
I couldn’t find the source listed in the book’s .
Please refer to the at the back of the report for more details on the statistical data.
Frequently Asked Questions
Plural for appendix (anatomy)?
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Plural for appendix (book/document)?
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What is the singular of appendix?
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Can I use ‘appendices’ for anatomy?
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Can I use ‘appendixes’ for a book?
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Yash, D. "What’s the Plural of Appendix? Appendixes or Appendices?." Grammarflex, Jun 6, 2025, https://www.grammarflex.com/whats-the-plural-of-appendix/.
Sources
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Synonyms of appendix
