cyan-1

1.
variant of cyano-1 , usually before a vowel or h: cyanamide.

cyan-2

1.
variant of cyano-2 , before a vowel.

cyan-3

1.
variant of cyano-3 , before a vowel.
British Dictionary definitions for cyan-

cyan-

combining form
1.
a variant of cyano- cyanamide, cyanide

cyano-

combining form
1.
blue or dark blue: cyanotype
2.
indicating cyanogen: cyanohydrin
3.
indicating cyanide
Word Origin
from Greek kuanos (adj) dark blue, (n) dark blue enamel, lapis lazuli