Definition of photoreactivation in US English:

photoreactivation

noun

Biology
  • The phenomenon whereby exposure of living material to visible light can counteract damage to genetic material caused by previous ultraviolet irradiation; an instance of this.

Origin

1940s. From photo- + reactivation.

Pronunciation

photoreactivation

/ˌfəʊtəʊrɪˌaktɪˈveɪʃn/