Compounds in which one or more of the ketone groups on the pyrimidine ring of barbituric acid are replaced by thione groups. ... (12 Dec 1998) ... 
Type: Term Pronunciation: thī′ō-bar-bi′chū-ritz Definitions: 1. Hypnotics of the barbiturate group, thiopental, in which the oxygen atom at carbon-2 is replaced by sulfur.