An Etymological Dictionary of Astronomy and Astrophysics

The time of day when the Sun crosses the observer’s meridian and is at its highest point above the horizon. At this point, the Sun lies due south of an observer in the northern hemisphere and due north of an observer in the southern hemisphere.

Etymology (EN): M.E. none; O.E. non, from L. nona hora “ninth hour” of daylight by Roman reckoning, about 3 p.m.

Etymology (PE): Nimruz, from nim “mid-, half” (Mid.Pers. nêm, nêmag “half;” Av. naēma- “half;” cf. Sk. néma- “half”) + ruz→ day.