sulphindigotic Meaning, Definition & Usage

Sulph*in`di*got"ic adjective
Definitions
  1. (Chem.) Of, pertaining to, or designating, a sulphonic acid obtained, as a blue solution, by dissolving indigo in sulphuric acid; -- formerly called also cerulic sulphuric acid, but properly called indigo-disulphonic acid.

Webster 1913