Definition of metachromism in English:

metachromism

Pronunciation /ˌmɛtəˈkrəʊmɪz(ə)m/

noun

Zoology
  • A sequence of evolutionary change in mammalian coat colour, consisting of loss of agouti patterning and reduction in pigmentation.

Origin

Late 19th century (in an earlier sense). From meta- + -chromism.