oxazine
/ˈɒksəziːn/Chemistry
noun
Any of a class of compounds whose molecules contain a ring of one nitrogen, one oxygen, and four carbon atoms, some of which are used as dyes; specifically a monocyclic compound with this structure and the formula C4H5NO.
Origin
Late 19th century; earliest use found in Journal of the Society of Chemical Industry. From German Oxazin from a rearrangement of Azoxin from az- + oxy- + -in.