Property of some crystals in which radiation polarized in one plane relative to the crystalline axes is freely transmitted, but radiation polarized perpendicular to this is absorbed. Tourmaline is a natural mineral with this property; Polaroid is a synthetic dichroic substance.
From Gk. dichro(os), from di- "two," → di-, + chroma "color" + -ism.
Dofâmi, from do "two," → bi- + fâm "color," + -i noun suffix.