Source : Webster's Revised Unabridged Dictionary (1913)

Meridional \Me*rid"i*o*nal\, a. [F. m['e]ridional, L.
   meridionalis, fr. meridies midday. See {Meridian}.]
   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.

Source : WordNet®

meridional
     adj 1: of or relating to a meridian
     2: located in the south or characteristic of southern people or
        places