• (n.) The blue coloring matter of flowers; -- called also anthokyan and anthocyanin.
Cy'a·nin noun [ See Cyanic .] (Chemistry) The blue coloring matter of flowers; -- called also anthokyan and anthocyanin . 
Cyanin (also known as anthokyan and anthocyanin) is the blue colouring matter of certain flowers, such as the violet and corn-flower. The name is also given to a pigment obtained from those petals of flowers which are blue by digesting them in spirits of wine.