DuckCorp Dico

Found one definition

1.                 From WordNet (r) 3.0 (2006):
                   
   
   
                   
                     
   sac
       n 1: an enclosed space; "the trapped miners found a pocket of
            air" [syn: pouch, sac, sack, pocket]
       2: a case or sheath especially a pollen sac or moss capsule
          [syn: theca, sac]
       3: a member of the Algonquian people formerly living in
          Wisconsin in the Fox River valley and on the shores of Green
          Bay [syn: Sauk, Sac]
       4: a structure resembling a bag in an animal