Addendum vs. Appendix — What's the Difference?

An addendum or appendix, in general, is an addition required to be made to a document by its author subsequent to its printing or publication. It comes from the Latin gerundive addendum, plural addenda, "that which is to be added," from addere (lit. ''give toward'', compare with memorandum, agenda, corrigenda).

An appendage.

An item of additional material added at the end of a book or other publication.

A collection of supplementary material, usually at the end of a book.

The radial distance from the pitch circle of a cogwheel or wormwheel to the crests of the teeth or ridges.

(Anatomy) Any of several supplementary or accessory parts of a bodily organ or structure, especially the vermiform appendix of the large intestine.

Something added or to be added, especially a supplement to a book.

Something attached to something else; an attachment or accompaniment.

Something to be added; especially text added as an appendix or supplement to a document.

A text added to the end of a book or an article, containing additional information.

A postscript.

(anatomy) The vermiform appendix.

(engineering) The height by which the tooth of a gear projects beyond (outside for external, or inside for internal) the standard pitch circle or pitch line.

(anatomy) Any process, prolongation, or projection.

A thing to be added; an appendix or addition.

Something appended or added; an appendage, adjunct, or concomitant.

Textual matter that is added onto a publication; usually at the end

Any literary matter added to a book, but not necessarily essential to its completeness, and thus distinguished from supplement, which is intended to supply deficiencies and correct inaccuracies.

The vermiform appendix.

Supplementary material that is collected and appended at the back of a book

A vestigial process that extends from the lower end of the cecum and that resembles a small pouch