A tranquillizer is a means of rest. In psychopharmacology, a distinction is made between two types of tranquillizers:
The minor tranquillizers form a large group with many different applications. Generally, with a tranquillizer is meant a tranquilizer such as Valium, Librium or Seresta. Some tranquillizers are also used as muscle relaxants, anti-epileptic drugs or for the suppression of withdrawal symptoms in alcohol addiction.
In medicine and medical literature, the term tranquillizer is not often used anymore.
wiki
