ataractic

From Ancient Greek ἀτάρακτος (atáraktos, “intrepid”), from ταράσσω (tarássō).

ataractic (comparative more ataractic, superlative most ataractic)

(pharmacology) That has a tranquilizing effect.
- 1961, Harry E. Wedeck, Dictionary of Aphrodisiacs, New York: The Citadel Press, page 59:
  Some drugs produce vivid hallucinations, others induce a relaxed condition, or are ataractic in their effect, that is, promote temporary tranquility[.]
- 2013, Einar Kringlen, Heredity and Environment in the Functional Psychoses, Elsevier, →ISBN, page 180:
  Later on he was treated by the same psychiatrist with ataractic drugs.