Prussian blue Meaning, Definition & Usage

  1. noun any of various blue pigments
    iron blue.
  2. noun a dark greenish-blue color

WordNet

Definitions
  1. (Chem.), any one of several complex double cyanides of ferrous and ferric iron; specifically, a dark blue amorphous substance having a coppery luster, obtained by adding a solution of potassium ferrocyanide (yellow prussiate of potash) to a ferric salt. It is used in dyeing, in ink, etc. Called also Williamson's blue, insoluble Prussian blue, Berlin blue, etc.
Definitions
  1. . See under Prussian.

Webster 1913