Dictionary
truth' se"rum
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.
Also,truth' drug".Cf.
narcoanalysis. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.