IPA: /əˈmɛndər/
KK: /əˈmɛndər/
A person who makes changes or improvements to something, often to correct or enhance it.
The amender proposed several changes to the document to improve clarity.
Amender is formed from "amend" (from Old French *amender*, meaning to correct or improve) and "-er" (meaning a person who). An amender is a person who corrects or improves something.
Think of someone who is 'correcting' or 'improving' something — that's what an amender does.