The Zenith of the Sun is a term used in astronomy to refer to the highest point that the sun reaches in the sky during the day. This occurs when the sun is directly overhead, or at the highest point in its daily arc across the sky.
The Zenith of the Sun at Angkor Wat
The term zenith sometimes means the highest point, way, or level reached by a celestial body on its daily apparent path around a given point of observation.