Pleader (noun)

1. A person who argues on behalf of another in a legal court.
2. A person who makes a case or argument for something.

Origin:

Middle english (in the sense "one who pleads a cause"): from old french plaidour, from plaidier "to plead", from latin placitare "to ask, entreat".

Examples:

1. The pleader was a skilled orator and was able to effectively argue the client's case.
2. The pleader was able to present compelling evidence in support of their argument.
3. The pleader's impassioned speech moved the jury to acquit the defendant.
4. The pleader was hired to represent the interests of the community in the lawsuit.
5. The pleader made a strong plea for clemency on behalf of the condemned man.