a person or thing that tranquilizes; esp., a depressant drug used as a calming agent in relieving and controlling various emotional disturbances, anxiety neuroses, certain psychoses, etc.
- One that serves to tranquilize, as soothing music.
- Any of various drugs used to reduce tension or anxiety; an antianxiety agent.
- Any of various drugs used to treat psychotic states; an antipsychotic drug. Not in scientific use.