An appendix is extra material attached at the end of a document. See the appendix, three appendices, in Appendix B.
The plural is appendices in writing and appendixes for the organ. Appendices hold the data, tables and detail that would clog the argument, and the rule is that anything essential belongs in the main text. The other sense is the small pouch attached to the large intestine, whose removal is an appendectomy — and appendicitis is one of the commonest emergency operations there is.
1nounappendixExtra material attached at the end of a document.
“The full results of the survey are given in an appendix at the end of the report.”
2nounsmallA small pouch attached to the large intestine.
“The appendix was removed at about four in the morning.”
appendix is an attached extra.
Latin
appendix
English, today
appendix
Borrowed from Latin appendix.
Etymology from Wiktionary, CC BY-SA
Practised in Academic English, Libraries & Museums