The Spanish word 'sol' meaning 'sun' comes directly from the Latin word 'sol' with the same meaning. This is one of the most straightforward etymologies possible, as the word has remained completely unchanged in both form and meaning since Latin times.

Several common Spanish words are derived from 'sol', including: 'soleado' (sunny), 'parasol' (sunshade), 'girasol' (sunflower, literally 'sun-turner'), and 'solar' (solar, relating to the sun). The word 'sol' is also used in the common expression 'tomar el sol' which means 'to sunbathe'.

Many English words are related to the Latin 'sol', including: 'solar', 'solarium', 'parasol', and 'solstice' (which literally means 'sun standing still'). The scientific term for studying the sun, 'solar physics', also uses this root. While English uses the Germanic word 'sun' rather than the Latin-derived 'sol' for the celestial body itself, we still preserve the Latin root in many technical and derived terms.