sydnone
noun
syd·none
ˈsidˌnōn
plural -s
: any of a class of heterocyclic compounds that contain a ring composed of two carbon atoms, two nitrogen atoms, and a fifth atom (such as oxygen) and have an oxo or similar group, that are resonance hybrids of several ionic states and have large dipole moments, and that are obtainable in various ways (as by dehydration of N-nitroso-N-phenyl-glycine by acetic anhydride)
Word History
Etymology
Sydney, Australia (where this type of compound was discovered) + English -one