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What’s the Plural of Appendix? Appendixes or Appendices?

Appendixes is the plural of appendix when referring to anatomy. Appendices is plural in reference to a book or document.

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.‍

Appendices/appendixes in sentence examples.

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.

indexindexes and indices
matrixmatrices and matrixes
appendixappendices or appendexes
codexcodices or codexes
vortexvortices or vortexes
vertexvertices or vertexes
apexapices or apexes

“Appendix”, used in sentences

  1. 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 |, 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)”.


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Whose vs who’s?


  1. Synonyms of appendix
  2. Sentence examples of appendices
  3. Origin of appendix.

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