pyrimidine

n. heterocyclic organic compound, weak organic base; derivative of this base (esp. one that is a component of DNA or RNA)

Pyrimidine is a heterocyclic aromatic organic compound similar to benzene and pyridine, containing two nitrogen atoms at positions 1 and 3 of the six-member ring. It is isomeric with two other forms of diazine.
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Pyrimidine /py·rim·i·dine/ an organic compound, C4H4N2, the fundamental form of the pyrimidine bases, including uracil, cytosine, and thymine. [more]Pyrimidine - Community and Resources

Noun
1. any of several basic compounds derived from pyrimidine
(hypernym) base, alkali
(hyponym) cytosine, C
2. a heterocyclic organic compound with a penetrating odor
(hypernym) organic compound

n. pyrimidine, heterocyclic organic compound, weak organic base; derivative of this base (esp. one that is a component of DNA or RNA)