additament
/ædɪˈtæmənt/Definitions
1. noun
Something added or attached to something else, especially a document or statement added to a legal or official document.
“The judge accepted the additament to the original contract, thus making the new terms binding.”
2. noun
A statement or claim added to a document or record, often as a rider or appendix.
“The researcher included an additament to her dissertation, detailing the methodology and results of her study.”