truth serum

[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/.
Compare narcoanalysis.

Origin of truth serum

First recorded in 1920–25 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for truth serum

Pentothal, scopolamine

Examples from the Web for truth serum

Historical Examples of truth serum

  • Then, abruptly, "Are you sure that was truth-serum in that hypodermic?"

    Man of Many Minds

    E. Everett Evans

  • So the doctors gave him truth-serum so he would not try to conceal anything from them.

    The Leader

    William Fitzgerald Jenkins (AKA Murray Leinster)

  • What sort of talents and abilities did he possess, that he could react thus to a truth-serum?

    Man of Many Minds

    E. Everett Evans

truth serum in Medicine

truth serum



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.