The Collaborative International Dictionary of English v.0.48:

Antarctic \Ant*arc"tic\, a. [OE. antartik, OF. antartique, F.
   antarctique, L. antarcticus, fr. Gr. ?; 'anti` + 'a`rktos
   bear. See Arctic.]
   Opposite to the northern or arctic pole; relating to the
   southern pole or to the region near it, and applied
   especially to a circle, distant from the pole 23[deg]
   28[min]. Thus we say the antarctic pole, circle, ocean,
   region, current, etc.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Antarctic
    adj 1: at or near the south pole [syn: south-polar,
           Antarctic]
    n 1: the region around the south pole: Antarctica and
         surrounding waters [syn: Antarctic, Antarctic Zone,
         South Frigid Zone]