Definition of radiations:
(n) :
The transfer of energy via radiation.
(n) :
The process of radiating waves or particles.
(n) :
The shooting forth of anything from a point or surface, like diverging rays of light.
(n) :
Radioactive energy.
(n) :
(evolutionary theory, countable) A rapid diversification of an ancestral species into many new forms.
(n) :
(often) Ellipsis of electromagnetic radiation. [Radiation (quantized as photons) consisting of oscillating electric and magnetic fields oriented perpendicularly to each other, moving through space.]