- A yellow crystalline compound, C6H4N2, having two fused six-member aromatic rings each containing two nitrogen atoms and four carbon atoms. One of the rings is a pyrimidine; the other is a pyrazine.
- Any of a group of organic compounds derived from this compound, including folic acid and the pigments of butterfly wings.
Origin of pteridineGerman Pteridin Pter(in) pigment of insect wings ( from Greek pteron wing ; see -pter . ) -id -ide -in -ine