Upholder (noun)

1. A person or thing that upholds or supports something.
2. A person who maintains or adheres to a particular tradition, principle, or law.

Origin:

From old english upphaldere, from upp- + holdere.

Examples:

1. She is an upholder of traditional values.
2. He is a strong upholder of the constitution.
3. The government is an upholder of democracy.
4. The company is an upholder of ethical standards.
5. The activist is a vocal upholder of human rights.