Definition of "cyanine" []

• Any of various blue dyes, used to sensitize photographic emulsions to a greater range of light. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Sulphon cyanine works well with other dye-stuffs, and gives shades which are fast to milling."
• "Unlike the former, cyanine, being composed of two old colours, can lay no claim to originality."
• "Within the last few years, a compound similar to cyanine has appeared, under the name of _Leitch's Blue_."