appendix

noun

ap·​pen·​dix ə-ˈpen-diks 

plural appendixes or appendices ə-ˈpen-də-ˌsēz 

1

a

: appendage

b

: supplementary material usually attached at the end of a piece of writing

The book's appendix includes a bibliography.

2

: a bodily outgrowth or process

specifically : vermiform appendix

Synonyms

• epilogue
• supplement
• documentation
• afterword
• addition
• addendum
• codicil
• conclusion

Examples of appendix in a Sentence

In your textbooks, turn to Appendix 3: Glossary of Terms.

The book has several appendixes.

Recent Examples on the Web

Appendix cancer may be treated with surgery, in which the appendix is removed. —Jacqueline Howard, CNN Money, 15 June 2025

Listen to this article 3 min Bindi Irwin is on the road to recovery and taking the time to heal after suffering a ruptured appendix earlier this month. —Tracy Wright, FOXNews.com, 26 May 2025

The Brazil international only had surgery to remove his appendix 13 days earlier, making a remarkable recovery and immediately getting back into action. —Adam Digby, Forbes.com, 10 May 2025

Believed to be made from a sheep’s appendix, the prophylactic dates back to 1830 and is likely a souvenir from a brothel, according to a statement from the Rijksmuseum in Amsterdam on Tuesday. —Jack Guy, CNN Money, 3 June 2025

Word History

Etymology

Latin appendic-, appendix, from appendere — see append

First Known Use

1542, in the meaning defined at sense 1a

Phrases Containing appendix

• vermiform appendix

Kids Definition

appendix

noun

ap·​pen·​dix ə-ˈpen-diks 

plural appendixes or appendices -də-ˌsēz 

1

: additional material attached at the end of a piece of writing

2

: a small tube that is closed at one end and projects from the pouch marking the beginning of the large intestine in the lower right side of the abdomen

Medical Definition

appendix

noun

ap·​pen·​dix ə-ˈpen-diks 

plural appendixes or appendices -də-ˌsēz 

: a bodily outgrowth or process

specifically : vermiform appendix