means Relating to the sun, or powered by the sun's light and heat.

from From Latin solaris, "of the sun," built on sol, the Latin word for the sun itself — a cousin of Greek helios and the source of names like Sol and the cheery Spanish sol. The same root warms English words from solstice (when the sun seems to "stand still") to solarium (a sun-room) and the sunny disposition of someone who is sol-arly inclined.