The Collaborative International Dictionary of English v.0.48:

Anthokyan \An`tho*ky"an\, n. [Gr. 'a`nqos flower + ky`anos
   blue.] (Chem.)
   The blue coloring matter of certain flowers. Same as
   Cyanin.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cyanin \Cy"a*nin\ (s?"?-n?n), n. [See Cyanic.] (Chem.)
   The blue coloring matter of flowers; -- called also
   anthokyan and anthocyanin.
   [1913 Webster]