diethylbarbituric acid, CHNO, a drug in the form of a white powder, used as a hypnotic and sedative: it is habit-forming and toxic
Origin:
barbit(uric acid) + -al
See barbital in American Heritage Dictionary 4
noun
A barbiturate, C8H12N2O3, that is a white crystalline powder and is used as a sedative and hypnotic especially in the form of its soluble salt, sodium barbital.