Extension and Supplement

Extension

Extension noun - The act of making longer.

Supplement is a synonym for extension in addition topic. In some cases you can use "Supplement" instead a noun "Extension", when it comes to topics like addendum, enlargement, annexe. 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

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

How words are described

full full extension full supplement
special special extension special supplement
common common extension common supplement
complete complete extension complete supplement
Other adjectives: separate, entire, large, obscure, final, incomplete, temporary, different, recent, optional, online.
Cite this Source
Supplement and Extension. (2016). Retrieved 2026, August 16, from https://thesaurus.plus/related/extension/supplement
Extension & Supplement. N.p., 2016. Web. 16 Aug. 2026. <https://thesaurus.plus/related/extension/supplement>.
Supplement or Extension. 2016. Accessed August 16, 2026. https://thesaurus.plus/related/extension/supplement.
Google Ngram Viewer shows how "extension" and "supplement" have occurred on timeline