noun
or phaeo·phy·tin ˌfēəˈfīd.ə̇n
Etymology: International Scientific Vocabulary pheo phorbide + phyt yl + -in
: a bluish black waxy pigment that is olive-brown in solution, that is obtained from chlorophyll by mild treatment with acid (as oxalic acid), and that differs from chlorophyll structurally only by the replacement of the magnesium atom in the molecule by two hydrogen atoms; the phytyl ester of pheophorbide