expert witness /ikspurt″, ek″spərt/ [L, experiri, to try; AS, witnes, knowledge] , a person who has special knowledge of a subject about which a court requests testimony. Special knowledge may be acquired by experience, education, observation, or study but is not possessed by the average person. An expert witness provides testimony or informed opinions on evidence. This evidence often serves to educate the court and the jury in the subject under consideration.
