Source : Webster's Revised Unabridged Dictionary (1913)

Phycocyanin \Phy`co*cy"a*nin\, Phycocyanine \Phy`co*cy"a*nine\,
   n. [Gr. ? seaweed + E. cyanin.]
   A blue coloring matter found in certain alg[ae].

Source : WordNet®

phycocyanin
     n : blue pigment in algae