Breadcrumb Home > Dictionary > Index A Cite alienist: Meaning and Definition of Find definitions for: al•ien•ist Pronunciation: (āl"yu-nist, ā"lē-u-), [key] — n. (formerly) a doctor specializing in the treatment of mental illness. an expert witness in a sanity trial. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: alienist (Thesaurus) alienism alienor TrendingHere are the facts and trivia that people are buzzing about. April 2021 Current Events: US News The Berlin Conference and the Partition of Africa The Implied Powers of Congress Noble Titles and Ranks in a Monarchy Keeping Your Brain Active in a COVID-19 World Quetzalcoatl: Aztec Myths and Myths About the Aztecs Related Content Daily Word Quiz: supertonic Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language