noun
- (formerly) a doctor specializing in the treatment of mental illness.
- an expert witness in a sanity trial.
noun
- US a psychiatrist who specializes in the legal aspects of mental illness
- obsolete a person who practises alienism
“one who treats mental illness, ‘mad doctor,’ ” 1864, from French aliĆ©niste, from alienation in the sense of “insanity, loss of mental faculty,” a sense attested in English from late 15c. (see alienate).
n.
- A physician accepted by a court of law as an expert on the mental competence of principals or witnesses.