depressant

noun

1. (countable, uncountable)A pharmacological substance which decreases neuronal or physiological activity.

   “Alcohol acts first as a stimulant and then as a depressant.”

   “The prescription painkiller Emily Jackson took is a respiratory depressant that slows breathing. That in combination with the alcohol, another respiratory depressant, overwhelmed her brain, which stopped giving her heart and lungs the signal to keep functioning.”

   “On the opposite end of the drug side effect spectrum are downers. This slang term refers to CNS depressants, the types of drugs that produce a sedative effect by slowing down the messages sent and received between the central nervous system and the brain.”

2. (countable, uncountable)An agent that inhibits the flotation of a mineral or minerals.

adj

1. Reducing functional or nervous activity.

   “the conception of the asomatous depressant malaria”