phycoerythrin Syllabification: (phy·co·e·ryth·rin)Pronunciation: /ˌfīkōˈerəTHrin, -iˈriTHrin/Definition of phycoerythrin noun Biochemistry any of a group of red photosynthetic pigments present in red algae and some cyanobacteria. phycoerythrin in other Oxford dictionaries Definition of phycoerythrin in the British & World English dictionary