The Collaborative International Dictionary of English v.0.48:

Southern \South"ern\ (?; 277), a. [AS. s[=u][eth]ern. See
   South.]
   Of or pertaining to the south; situated in, or proceeding
   from, the south; situated or proceeding toward the south.
   [1913 Webster]

   Southern Cross (Astron.), a constellation of the southern
      hemisphere containing several bright stars so related in
      position as to resemble a cross.

   Southern Fish (Astron.), a constelation of the southern
      hemisphere (Piscis Australis) containing the bright star
      Fomalhaut.

   Southern States (U.S. Hist. & Geog.), the States of the
      American Union lying south of Pennsylvania and the Ohio
      River, with Arkansas, Louisiana, and Texas. Before the
      Civil War, Missouri also, being a slave State, was classed
      as one of the Southern States.
      [1913 Webster]