depressant

/dɪˈprɛsənt/
noun
  1. A substance, such as a drug or alcohol, that slows down the activity of the brain and nervous system, making a person feel relaxed or sleepy.
    • The doctor warned that mixing depressants like sleeping pills with alcohol can be dangerous.
    • Alcohol is a depressant, which is why it can make people feel drowsy.
    • Some depressants are prescribed to treat anxiety or insomnia.
Antonyms
adjective
  1. Tending to reduce activity or excitement; having a calming or sedative effect.
    • Certain herbs are known for their mild depressant properties.
    • The depressant qualities of the drug help patients relax before surgery.
    • The medication has a depressant effect on the central nervous system.