from
The Collaborative International Dictionary of English v.0.48
Umbelliferone \Um`bel*lif"er*one\, n. (Chem.)
A tasteless white crystalline substance, {C9H6O3}, found in
the bark of a certain plant ({Daphne Mezereum}), and also
obtained by the distillation of certain gums from the
{Umbelliferae}, as galbanum, asafetida, etc. It is analogous
to coumarin. Called also {hydroxy-coumarin}. Its strong
fluorescence under ultraviolet light makes it useful in
analytical biochemistry, as, for example, to detect
phosphatase activity by hydrolysis of umbelliferyl phosphate.
[1913 Webster +PJC]