[mass noun]distance travelled or measured southward, especially at sea (尤指在海上的)南行航程 ■[count noun]a figure or line representing southward distance on a map 地图上代表南行距离的数字或线 ■(Astronomy)the transit of a celestial object, especially the sun, across the meridian due south of the observer (天文)南中天 ■[count noun](Astronomy)the angular distance of a star or other object south of the celestial equator (天文)南赤纬