The Collaborative International Dictionary of English v.0.48:

Ant \Ant\, n. [OE. ante, amete, emete, AS. [ae]mete akin to G.
   ameise. Cf. Emmet.] (Zool.)
   A hymenopterous insect of the Linn[ae]an genus Formica,
   which is now made a family of several genera; an emmet; a
   pismire.
   [1913 Webster]

   Note: Among ants, as among bees, there are neuter or working
         ants, besides the males and females; the former are
         without wings. Ants live together in swarms, usually
         raising hillocks of earth, variously chambered within,
         where they maintain a perfect system of order, store
         their provisions, and nurture their young. There are
         many species, with diverse habits, as agricultural
         ants, carpenter ants, honey ants, foraging ants, amazon
         ants, etc. The white ants or Termites belong to the
         Neuroptera.
         [1913 Webster]

   Ant bird (Zool.), one of a very extensive group of South
      American birds (Formicariid[ae]), which live on ants.
      The family includes many species, some of which are called
      ant shrikes, ant thrushes, and ant wrens.

   Ant rice (Bot.), a species of grass (Aristida oligantha)
      cultivated by the agricultural ants of Texas for the sake
      of its seed.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ant bird \Ant" bird\, (Zool.)
   See Ant bird, under Ant, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

ant bird
    n 1: any of various dull-colored South American birds that
         feeding on ants some following army ant swarms [syn:
         antbird, ant bird]