Maker of a change or revision

• Bill of Rights writer, e.g.
• Change maker
• One changing a bill
• Bill modifier, e.g
• Editor, at times
• Copyreader, e.g
• Unexpectedly named by Queen, one changing for the better?

Wiktionary Word definitions in Wiktionary
n. One who amends.

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Amender \A*mend"er\, n. One who amends.