insolation

The act or an instance of exposing to sunlight.

Therapeutic exposure to sunlight.

The solar radiation striking Earth or another planet.

The rate of delivery of solar radiation per unit of horizontal surface.

Exposure to the sun's rays; subjection to the influence of solar heat and light, as for drying, maturing, or the production of chemical action; in medicine, treatment by exposure to the sun, in order to stimulate the vital forces.