expert witness

Definitions

Construction

  • In a court case or other legal or arbitration proceeding, an individual who, because of his/her exceptional knowledge, experience, or skill in a particular field or subject, is accepted by the court (or by those presiding over other legal or arbitration proceedings) as being qualified to render an authoritative opinion in matters relating to his or her field of expertise.

Law

http://www.dictionarycentral.com/definition/expert-witness.html