expert witness

English Thesaurus

1. a witness who has knowledge not normally possessed by the average person concerning the topic that he is to testify about (noun.person)

hypernym	:	witness,
definition	:	(law) a person who testifies under oath in a court of law (noun.person)

antonym	:	lay witness,
definition	:	any witness who does not testify as an expert witness (noun.person)

antonym	:	lay witness,
definition	:	any witness who does not testify as an expert witness (noun.person)