English - Etymology
From Middle English, from Old French, from Latin meridianus (“of or belonging to midday or to the south, southern”), from meridies (“midday, the south”), originally *medidies, from medius (“middle”) + diēs (“day”).
English - Noun
- An imaginary great circle on the Earth's surface, passing through the geographic poles.
- Either half of such a great circle, all points of which have the same longitude.
- (astronomy) A great circle passing through the poles of the celestial sphere and the zenith for a particular observer.
- (mathematics) A similar line on any general surface of revolution.
- (alternative medicine) Any of the pathways on the body along which the vital energy is thought to flow and, therefore, the acupoints are distributed.
- The highest point, as of success, prosperity, etc.; culmination.