[in.so.la.tion] n [F or L; F, fr. L insolation-, insolatio, fr. insolare to expose to the sun, fr. in- + sol sun--more at solar] (1617) 1: exposure to the sun's rays
2: sunstroke 3 a: solar radiation that has been received b: the rate of delivery of direct solar radiation per unit of horizontal surface; broadly: that relating to total solar radiation