[ uh-pen-diks ]
/ əˈpɛn dɪks /

noun, plural ap·pen·dix·es, ap·pen·di·ces [uh-pen-duh-seez] /əˈpɛn dəˌsiz/.

supplementary material at the end of a book, article, document, or other text, usually of an explanatory, statistical, or bibliographic nature.
  1. a process or projection.
  2. vermiform appendix.
Aeronautics. the short tube at the bottom of a balloon bag, by which the intake and release of buoyant gas is controlled.

Nearby words

  1. appendicular artery,
  2. appendicular muscle,
  3. appendicular skeleton,
  4. appendicular vein,
  5. appendiculate,
  6. appentice,
  7. appenzell,
  8. appenzell ausser rhoden,
  9. appenzell inner rhoden,
  10. appenzeller

Origin of appendix

1535–45; < Latin: appendage, equivalent to append(ere) to append + -ix (equivalent to -ic- noun suffix + -s nominative singular ending)

Can be confusedappendix index supplement (see synonym study at the current entry)

Synonym study

Appendix, supplement both mean material added at the end of a book. An appendix gives useful additional information, but even without it the rest of the book is complete: In the appendix are forty detailed charts. A supplement, bound in the book or published separately, is given for comparison, as an enhancement, to provide corrections, to present later information, and the like: A yearly supplement is issued.

Usage note

Appendices, a plural borrowed directly from Latin, is sometimes used, especially in scholarly writing, to refer to supplementary material at the end of a book. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for appendix

British Dictionary definitions for appendix


/ (əˈpɛndɪks) /

noun plural -dices (-dɪˌsiːz) or -dixes

a body of separate additional material at the end of a book, magazine, etc, esp one that is documentary or explanatory
any part that is dependent or supplementary in nature or function; appendage
anatomy See vermiform appendix

Word Origin for appendix

C16: from Latin: an appendage, from appendere to append

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for appendix



1540s, "subjoined addition to a document or book," from Latin appendix "an addition, continuation, something attached," from appendere (see append). Used for "small outgrowth of an internal organ" from 1610s, especially in reference to the vermiform appendix. This sense perhaps from or influenced by French appendix, where the term was in use from 1540s.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for appendix


[ ə-pĕndĭks ]

n. pl. ap•pen•dix•es

A supplementary or an accessory part of an organ or a structure of the body.
The vermiform appendix.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for appendix


[ ə-pĕndĭks ]

Plural appendixes appendices (ə-pĕn-dĭ-sēz′)

A tubular projection attached to the cecum of the large intestine and located on the lower right side of the abdomen. Also called vermiform appendix
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Culture definitions for appendix


A small saclike organ located at the upper end of the large intestine. The appendix has no known function in present-day humans, but it may have played a role in the digestive system in humans of earlier times. The appendix is also called the vermiform appendix because of its wormlike (“vermiform”) shape.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.