The Collaborative International Dictionary of English v.0.48:

Amazon \Am"a*zon\, n. [L., fr. Gr. ?.]
   1. One of a fabulous race of female warriors in Scythia;
      hence, a female warrior.
      [1913 Webster]

   2. A tall, strong, masculine woman; a virago.
      [1913 Webster]

   3. (Zool.) A name numerous species of South American parrots
      of the genus Chrysotis
      [1913 Webster]

   Amazon ant (Zool.), a species of ant (Polyergus
      rufescens), of Europe and America. They seize by conquest
      the larv[ae] and nymphs of other species and make slaves
      of them in their own nests.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Amazon ant
    n 1: small reddish slave-making ant species [syn: Amazon ant,
         Polyergus rufescens]