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

• addendum
• afterword
• codicil
• excursus
• supplement

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

Lévêque was 9 years old when her appendix was removed by the surgeon. —Linda Hervieux, NBC News, 23 Feb. 2025

The release of the redacted appendix, which was an attachment to the immunity motion unsealed two weeks ago by U.S. District Judge Tanya Chutkan that included new details about Trump and his allies' actions leading up to the Jan. 6 assault on the Capitol, is currently scheduled for Thursday. —Alexander Mallin, ABC News, 17 Oct. 2024

Parts of that appendix are currently being used by NSF staff to screen thousands of their active grants for compliance with President Trump's executive orders targeting diversity, equity and inclusion measures across the government. —Jonathan Lambert, NPR, 13 Feb. 2025

The memo included an appendix with names of the employees who would be fired. —Pat Milton, CBS News, 31 Jan. 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