Definition of appendix in English:

Share this entry


Pronunciation: /əˈpendiks/

noun (plural appendices /-diˌsēz/; appendixes)

1 Anatomy A tube-shaped sac attached to and opening into the lower end of the large intestine in humans and some other mammals. Also called vermiform appendix.

In humans the appendix is small and has no known function, but in rabbits, hares, and some other herbivores it is involved in the digestion of cellulose.

Example sentences
  • The inside of the appendix forms a cul-de-sac that usually opens into the large intestine.
  • This is a rare tumour that usually affects the appendix or the small intestine.
  • The myenteric plexus of appendices in children older than 3 years had thinner nerve branches and smaller ganglia than the colon specimens of the same age.
2A section or table of additional matter at the end of a book or document.
Example sentences
  • His recipe for this amalgam is included as an appendix to the present book.
  • The book contains appropriate appendixes, which document the evolutionary improvement of tank formations, and excellent photographs, and maps that adequately depict the war.
  • In an appendix to Volume 2, the author addresses the question of how people were saved in Old Testament times before the coming of Christ.
supplement, addendum, postscript, codicil;
coda, epilogue, afterword, tailpiece, back matter;


Appendix typically has the plural appendixes in the anatomical sense, and appendices when referring to a part of a book or document.


Mid 16th century (sense 2): from Latin, from appendere 'hang upon' (see append). Sense 1 dates from the early 17th century.

  • The appendix is a tube-shaped sac attached to the lower end of the large intestine. The word comes directly from Latin and is based on appendere ‘to hang on’, the source of other English words such as append (Late Middle English), and appendage (mid 17th century). It is first recorded in the sense ‘section of extra matter at the end of a book or document’, the anatomy term appears early in the 17th century.

For editors and proofreaders

Syllabification: ap·pen·dix

Share this entry

What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.