ˈpirəˌdōn noun
( -s )
Etymology: International Scientific Vocabulary pyrid- + -one
: any of several isomeric carbonyl compounds C 5 H 5 NO derived from pyridine: as
a. : the crystalline alpha isomer — called also 2-pyridone, 2(1 H )-pyridone
b. : the crystalline gamma isomer — called also 4-pyridone, 4(1 H )-pyridone