Definition of photopathy in English:

photopathy

noun

Biology
rare
  • Originally: the tendency of an organism to move either into or away from regions of relatively intense illumination (as distinct from a response specifically to the direction of the light rays). In later use: a tendency to move out of more brightly lit areas (negative phototaxis); intolerance of light.

Origin

Late 19th century. From photo- + -pathy Compare photophil.

Pronunciation

photopathy

/fəʊˈtɒpəθi/