solar
of the sun
Today this word meansRelating to the sun, as in solar power and the solar system.
From Latin sol, and the Roman sun god Sol bears the same name.
Sol being the Roman counterpart of Helios, the Greek-derived helio- and the Latin-derived solar run side by side with the same meaning.
Worth noting
The word did not come from the god's name; the same word simply doubled as his name.