me.rid.i.ann.Abbr. m.,M.,mer.(名词)缩写 m.,M.,mer.An imaginary great circle on the earth`s surface passing through the North and South geographic poles. All points on the same meridian have the same longitude.过两极的大圆:一个通过地球表面南北两极的假想线圈。同一子午线上的所有点都具有相同的经度Ei...