bar·bi·tu·ric acid 
(bär′bĭ-trĭk, -tyr-)
(bär′bĭ-trĭk, -tyr-)n.
An acidic pyrimidine derivative, C4H4O3N2, used in the manufacture of barbiturates and some plastics.
[Partial translation of German Barbitursäure (coined by German chemist Adolf von Baeyer (1835-1917), purportedly after he discovered the compound on December 4, 1864, the feast of Saint BARBARA, by combining malonic acid and urea) : Barbit- (irregularly derived from the name Barbara) + New Latin ūr(ea), urea; see UREA + German Säure, acid.]