(n)a deficiency of color vision in which the person can match any given hue by mixing only two other wavelengths of light (as opposed to the three wavelengths needed by people with normal color vision), Syn.dichromatism, dichromia, dichromatopsia, dichromasy
The Collaborative International Dictionary of English (GCIDE) v.0.53Collaborative International Dictionary (GCIDE)
a. [ Pref. di- + chromatic: cf. Gr. &unr_;. ] 1. Having or exhibiting two colors. [ 1913 Webster ]
2. (Zool.) Having two color varieties, or two phases differing in color, independently of age or sex, as in certain birds and insects. [ 1913 Webster ]