barbiturate

n. drug used as a sedative

Barbiturates are drugs that act as central nervous system depressants, and by virtue of this they produce a wide spectrum of effects, from mild sedation to anesthesia. Some are also used as anticonvulsants.Barbiturates are derivatives of barbituric acid.
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Barbiturate /bar·bi·tur·ate/ any of a class of compounds derived from barbituric acid ; used for their hypnotic and sedative effects. [more]Barbiturate - Community and Resources

Noun
1. organic compound having powerful soporific effect; overdose can be fatal
(hypernym) sedative-hypnotic, sedative-hypnotic drug
(hyponym) amobarbital

n. barbital, sleep inducing drug, sedative