appendix

appendix — noun

1. an extra part placed after the main text of a book, report, or document, holding

1.nounB2
Definition

an extra part placed after the main text of a book, report, or document, holding details such as tables, raw data, or background notes that support the main content but would interrupt it.

Example

The full survey results are listed in Appendix B at the back of the report.

labelled appendix: Appendix A, B, C

Professor Lin added an appendix to her cookbook with measurement charts for new bakers.

appendix to + book

Common collocations
  • see the appendix
  • in the appendix
  • attach an appendix
  • appendices A, B, C
Synonyms
  • supplement

    broader; can be a separate booklet, not always at the end

  • annex

    common in legal or government documents

  • addendum

    shorter, often added after the document was first finished

Grammar Patterns

appendix to + book/document/report

Usage Note

Plural is usually 'appendices' for this sense (books, reports, legal documents). The single-word phrase 'see appendix' often appears in academic writing to point readers to supporting material.

Common Mistakes

I put the photos in the appendix of my email.
I attached the photos to my email.
'appendix' is for books and formal documents, not for everyday emails.
The contract has two appendix.
The contract has two appendices.
countable noun; use the plural form.

2. a small finger-shaped tube that hangs off the lower right side of the large inte

2.nounB2
Definition

a small finger-shaped tube that hangs off the lower right side of the large intestine, has no clear job in the human body, and sometimes becomes infected and must be removed.

Example

Doctors removed Sofia's appendix on Tuesday after she felt sharp pain in her lower right side.

remove + appendix (surgical context)

Rashida woke up at midnight clutching his stomach; his appendix had burst.

appendix burst (medical emergency)

Common collocations
  • remove the appendix
  • burst appendix
  • inflamed appendix
  • appendix surgery
Synonyms

Grammar Patterns

the appendix

Usage Note

Plural in this anatomical sense is usually 'appendixes' (in American medical writing) or 'appendices' (in British texts) — both are accepted. Distinguish from sense 1: this one is always physical and singular when referring to one person.

Common Mistakes

The doctor took out my appendices.
The doctor took out my appendix.
each person has only one.
I have appendix.
I have appendicitis.
the illness has its own name; 'appendix' alone is just the body part.

Word family

  • appendices
    nounB2
  • appendixes
    nounB2
  • appendicitis
    nounC1
  • append
    verbC1
  • appended
    adjectiveC1

Synonym discussion

Sense: noun/1

All four words name extra material added to a main text, but they differ in scope and register. An 'appendix' is a planned section at the end of a book or report holding supporting data, charts, or transcripts — written in advance as part of the document. A 'supplement' is broader and often physically separate: a magazine's weekend supplement, or a supplement booklet sold with a textbook. An 'addendum' is short and added after the main work was already considered finished, often to correct or update something. 'Annex' is most common in legal, government, or treaty documents, where it labels attached schedules. So you write an appendix while drafting; you publish a supplement alongside; you slip in an addendum afterwards; you cite an annex in a contract.

appendix ↗supplement ↗addendumannex ↗

Common collocations

Nouns

  • appendix entry
  • appendix section
  • appendix surgery
  • appendix pain

Phrases

  • see appendix
  • as shown in the appendix
  • removal of the appendix

Prepositions

  • in the appendix
  • to the appendix
  • from the appendix

Etymology

LatinEnglish

Borrowed into English in the mid-1500s from Latin 'appendix', meaning something hung onto or attached to a larger thing. The Latin word came from the verb 'appendere' ('to hang onto'), built from 'ad-' ('to') and 'pendere' ('to hang'). It first described extra writing tacked onto a book, then in the 1600s anatomists adopted it for the small tube on the intestine because it 'hangs off' the gut in a similar way. The two modern senses — book section and body part — share this root idea of one small thing attached to something larger.