Any of a group of cyanine dyes which are quaternary iodides derived from lepidine and were formerly used to sensitize photographic emulsions and plates to infrared light.
Origin
1920s.
Definition of neocyanine in US English:
neocyanine
noun
Chemistry
Any of a group of cyanine dyes which are quaternary iodides derived from lepidine and were formerly used to sensitize photographic emulsions and plates to infrared light.