-əˌrōn noun
( -s )
Etymology: International Scientific Vocabulary umbellifer + -one, originally formed as German umbelliferon
: a crystalline phenolic lactone C 9 H 6 O 3 found in many plants, obtained by the distillation of resins (as galbanum or asafetida) from various umbellifers, and also made synthetically; 7-hydroxy-coumarin — compare herniarin