phenobarbital
phe·no·bar·bi·tal
noun \ˌfē-nō-ˈbär-bə-ˌtȯl, -tȧl\Definition of PHENOBARBITAL
: a crystalline barbiturate C12H12N2O3 that is used orally or is administered by injection in the form of its sodium salt C12H11N2NaO3 as a hypnotic and sedative—see luminal
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