Addendum and Supplement

Addendum

Addendum noun - A part added at the end of a book or periodical.
Usage example: there's an addendum from the author to explain certain stylistic choices that she made

Supplement is a synonym for addendum in addition topic. In some cases you can use "Supplement" instead the word "Addendum" as a noun or a verb, when it comes to topics like appendix, added. popular alternative

Supplement

Supplement noun - Something added (as by growth).
Usage example: this new rule restricting e-mail to job-related activity is only a supplement to the preexisting policy regarding personal use of company resources

Addendum is a synonym for supplement in appendix topic. You can use "Addendum" instead a noun "Supplement", if it concerns topics such as something added. popular alternative

How words are described

several several addendum several supplement
optional optional addendum optional supplement
Cite this Source
Supplement and Addendum. (2016). Retrieved 2026, August 15, from https://thesaurus.plus/related/addendum/supplement
Addendum & Supplement. N.p., 2016. Web. 15 Aug. 2026. <https://thesaurus.plus/related/addendum/supplement>.
Supplement or Addendum. 2016. Accessed August 15, 2026. https://thesaurus.plus/related/addendum/supplement.
Google Ngram Viewer shows how "addendum" and "supplement" have occurred on timeline