[trooth seer-uh m]
a drug, as the barbiturate thiopental, that induces in the subject a desire to talk or a state of heightened suggestibility, used in psychotherapy and in interrogation to discover repressed or consciously withheld information.
Often truth drug [trooth druhg] /ˈtruθ ˌdrʌg/.
Origin of truth serum
First recorded in 1920–25
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
informal any of various drugs supposed to have the property of making people tell the truth, as by relaxing them
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Any of various hypnotic or anesthetic drugs, such as scopolamine or thiopental sodium, used to induce a subject under questioning to talk without inhibition.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.