Interpreter (noun)

1. A person who translates spoken or written language from one language to another.
2. A person who explains or interprets something.

Origin:

From latin interpretem, from interpretari "explain, interpret".

Examples:

1. He acted as an interpreter for the foreign delegation.
2. She is a professional interpreter for the UN.
3. The interpreter translated the speech into Spanish.
4. The interpreter helped the deaf person to understand the lecture.
5. The interpreter was needed to translate the legal documents.