pīˈriməˌdēn, -_də̇n; ˈpirəməˌdēn noun
( -s )
Etymology: International Scientific Vocabulary, alteration of pyridine; probably originally formed as German pyrimidin
1. : a crystalline feeble heterocyclic base C 4 H 4 N 2 of penetrating odor that is usually prepared indirectly from barbituric acid; 1,3-diazine — compare purine , structural formula
2. : a derivative of pyrimidine ; especially : a base (as cytosine) that is a component of nucleosides and nucleotides