What does appendices mean?
'Appendices' is the plural form of 'appendix' and most commonly denotes the supplementary sections placed at the end of a book, report, dissertation, or other formal document. These sections carry material that would clutter the main text if included there — raw data tables, lengthy transcripts, legal documents, questionnaires, or extended statistical analyses — and they are typically labelled with letters or numbers (Appendix A, Appendix B) and referenced throughout the body of the work. The word carries a distinctly formal, academic tone: readers encounter it in scholarly papers, government reports, and technical manuals far more often than in casual conversation. Like several learned borrowings from Latin, 'appendix' retains its original Latin plural, so writers use 'appendices' rather than the anglicized 'appendixes'. A second, narrower sense arises in medicine, where the same plural describes more than one vermiform appendix — the small, finger-shaped pouch attached to the large intestine — as when anatomists discuss congenital duplication. Understanding 'appendices' helps readers navigate long documents efficiently and signals familiarity with formal written conventions.
nounThe plural of 'appendix': supplementary sections of additional material — such as tables, documents, or reference data — placed at the end of a book, report, or other document.
- Supplementary sections of material added at the end of a book, report, thesis, or other document.
- (As the plural of the anatomical term) multiple instances of the vermiform appendix, used chiefly in medical or veterinary contexts.
"The survey results are presented in full in one of the report's appendices."
"All raw data tables are provided in Appendices A through C."
"The surgeon noted two rare cases involving duplicated appendices."
'Appendices' is itself the standard plural of 'appendix'; the rarer anglicized alternative is 'appendixes'.
"The committee reviewed all five appendices before issuing its final recommendation."
Like 'index', 'appendix' keeps its Latin plural — so a thick report can hold several appendices but never 'appendixes' without raising an editor's eyebrow.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of appendices
'Appendices' comes from the Latin 'appendix', meaning 'an attachment' or 'something hung on', derived from the verb 'appendere', 'to hang upon', formed from 'ad-' ('toward') plus 'pendere' ('to hang'). English adopted the noun in the early modern period, and because it was borrowed directly from Latin it preserved the Latin plural 'appendices' alongside the later anglicized 'appendixes'. The same Latin root 'pendere' gives English a family of related words, including 'pendant', 'pendulum', 'suspend', and 'depend'.
Related word forms
How appendices is actually used
Formal and academic in register; almost always encountered in scholarly, technical, or professional writing. The Latin-style plural is strongly preferred over 'appendixes', though the latter occasionally appears informally. In medical contexts the same plural refers to the intestinal organ rather than to document sections.
Easily confused with appendices
'Appendix' is the singular form referring to either a supplementary document section or the small pouch attached to the intestine, while 'appendices' is simply its plural.
Like 'appendix', 'index' has two plural forms, but for 'appendix' only 'appendices' is standard, whereas 'index' may be pluralized as either 'indexes' or 'indices'.