alien·​ist ˈā-lē-ə-nist How to pronounce alienist (audio)
plural alienists

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What is the Connection Between alienist and Alien?

Alienist looks and sounds like it should mean "someone who studies aliens," and in fact alienist and alien are related—both are ultimately derived from the Latin word alius, meaning "other." In the case of alienist, the etymological trail leads from Latin to the French noun aliéniste, which refers to a doctor who treats the mentally ill. Alienist first appeared in print in English about mid-19th century. It was preceded by the other alius descendants, alien (14th century) and alienate (used as a verb since the 15th century). Alienist is much rarer than psychiatrist these days, but at one time it was a common term.

Example Sentences

Recent Examples on the Web The most expensive show produced by TNT is based on Caleb Carr’s best-selling 1994 historical thriller about a psychiatrist (or alienist, as they were once called) in Gilded Age New York who tries to catch a serial killer. Gabe Cohn, New York Times, 22 Jan. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'alienist.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


borrowed from French aliéniste, earlier as adjective in médecin aliéniste "doctor treating the mentally ill, psychiatrist," from aliéné "mentally ill person" (noun derivative from past participle of aliéner "to transfer to another's ownership, estrange, deprive of reason," going back to Middle French) + -iste -ist entry 2 — more at alien entry 3

First Known Use

1864, in the meaning defined above

Time Traveler
The first known use of alienist was in 1864


Dictionary Entries Near alienist

Cite this Entry

“Alienist.” Dictionary, Merriam-Webster, Accessed 28 Mar. 2023.

Medical Definition



Legal Definition


: a psychiatrist who specializes in the legal aspects of psychiatry (as determining sanity or capacity to stand trial)
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