phycobilin
noun
phy·co·bi·lin
| \ ˌfī-kō-ˈbī-lən
, -ˈbil-ən
\
, -ˈbil-ən
\
Medical Definition of phycobilin
: any of a class of pigments that occur in the cells of algae, are active in photosynthesis, and are proteins combined with pyrrole derivatives related to the bile pigments