noun ·Moderate ·College level

Definitions

Noun

1. 1
   Something to be added; especially text added as an appendix or supplement to a document.

   "An addendum was added to the contract to clarify payment terms."

2. 2
   textual matter that is added onto a publication; usually at the end wordnet
3. 3
   A postscript.
4. 4
   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.

Synonyms

All synonyms

accessionaccessoryaccidentaccidentalaccompanimentaddend

Example

More examples

"Notice the addendum to the last item on the first page."

Etymology

From the gerundive of Latin addere (“to add”).

Related phrases

pitch circlepitch line

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.