Me·rid·i·o·nal a.
  1. Of or pertaining to the meridian.
  2. Having a southern aspect; southern; southerly.
     Offices that require heat . . . should be meridional.   --Sir H. Wotton.
  Meridional distance, the distance or departure from the meridian; the easting or westing.
  Meridional parts, parts of the meridian in Mercator's projection, corresponding to each minute of latitude from the equator up to 70 or 80 degrees; tabulated numbers representing these parts used in projecting charts, and in solving cases in Mercator's sailing.
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