The Spanish word 'barbitúrico' (meaning 'barbituric') comes from French 'barbiturique', which in turn comes from the German word 'Barbitursäure' (barbituric acid). The German term is a compound created from three parts: the name 'Barbara', 'urat' (urate), and 'Säure' (acid). This chemical compound was first synthesized on December 4, 1864, which was St. Barbara's Day, hence the incorporation of the name Barbara into the scientific term. This etymology represents an interesting case where a personal name became part of scientific terminology due to a historical coincidence.

Being a relatively modern scientific term, 'barbitúrico' doesn't have many related simpler Spanish words. It's primarily used in medical and chemical contexts, often appearing in the term 'ácido barbitúrico' (barbituric acid) or in reference to 'barbitúricos' (barbiturates), which are a class of drugs derived from barbituric acid.

The English cognate 'barbituric' is virtually identical to the Spanish word, and both languages use related terms like 'barbiturate' (Spanish: 'barbitúrico' as a noun). These terms are part of the international scientific vocabulary and are very similar across many modern languages due to their recent common origin in German chemical terminology.