meridian

中文： 经线

1. In full celestial meridian: a great circle passing through the poles of the celestial sphere and the zenith for a particular point on the Earth's surface.
2. In full terrestrial meridian: a great circle on the Earth's surface, passing through the geographic poles (the terrestrial North Pole and South Pole); also, half of such a circle extending from pole to pole, all points of which have the same longitude.
3. The place on the celestial meridian where it is crossed by the sun or a star at its highest point.
4. The highest or most developed point, or most splendid stage, of something; culmination, peak, zenith. (figuratively)
5. Chiefly followed by of: the middle period of someone's life, when they are at their full abilities or strength; one's prime. (figuratively)
6. A ring or half-ring with markings in which an artificial globe is installed and may spin.
7. A line passing through the poles of any sphere; a notional line on the surface of a curved or round body (in particular, an eyeball).
8. The size of type between double great primer and canon, standardized as 44-point. (US, dated)

复数 meridians