The American Heritage® Dictionary of the English Language, 4th Edition
n. Any of several stable, light-fast, blue or green organic pigments derived from the basic compound (C6H4C2N)4N4 and used in enamels, printing inks, linoleum, and plastics.
n. Any of a family of macrocyclic compounds having a structure similar to that of porphyrin; they are blue/green pigments that are used in plastics and enamels
Word Usage
"Their small size enables them to easily enter cells, and the phthalocyanine is taken up along with them."