vindicator
/vɪnˈdɪkteɪtər/Definitions
1. noun
A person or thing that defends or justifies something, especially a cause or a person.
“The whistleblower became a powerful vindicator for transparency in government.”
2. verb
To defend or justify something, especially a cause or a person.
“The activist set out to vindicate the rights of the oppressed community.”