Narcotic

adj. of or associated with drug addicts; of or pertaining to addictive substances which dull the senses; pertaining to sedative or pain relieving medical drugs; of narcotism; causing narcotism

n. any addictive substance which dulls the senses (morphine, opium, alcohol, etc.); opium and its derivatives; medical drug for pain relief and sedation; relaxant, barbiturate; drug addict

The term narcotic (ναρκωτικός) is believed to have been coined by Galen to refer to agents that benumb or deaden, causing loss of feeling or paralysis. The term is based on the Greek word ναρκωσις (narcosis), the term used by Hippocrates for the process of benumbing or the benumbed state. Galen listed mandrake root, altercus (eclata) seeds, and poppy juice (i.e. opium) as the chief examples.
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Noun
1. a drug that produces numbness or stupor; often taken for pleasure or to reduce pain; extensive use can lead to addiction
(hypernym) drug
(hyponym) hard drug
(derivation) narcotize, narcotise
(class) connection
Adjective
1. of or relating to or designating narcotics; "narcotic addicts"; "narcotic stupor"
2. inducing stupor or narcosis; "narcotic drugs"
(synonym) narcotizing, narcotising
(similar) depressant
3. inducing mental lethargy; "a narcotic speech"
(synonym) soporiferous, soporific
(similar) uninteresting

(n.)
A drug which, in medicinal doses, generally allays morbid susceptibility, relieves pain, and produces sleep; but which, in poisonous doses, produces stupor, coma, or convulsions, and, when given in sufficient quantity, causes death. The best examples are opium (with morphine), belladonna (with atropine), and conium.
  

(a.)
Having the properties of a narcotic; operating as a narcotic.
  

An agent that causes insensibility or stupor; usually refers to opioids given to relieve pain.