pentobarbitone

 
Pronunciation: /ˌpɛntə(ʊ)ˈbɑːbɪtəʊn/
(US pentobarbital)

noun

[mass noun] Medicine
  • a narcotic and sedative barbiturate drug formerly used to relieve insomnia.
    • Alternative name: 5-ethyl-5-(1-methylbutyl)-barbituric acid; often used as the sodium salt ( sodium pentobarbitone, Nembutal)

Origin:

1930s: from pentane + barbitone (or barbital)