The Collaborative International Dictionary of English v.0.48:

Ionic \I*on"ic\, n.
   1. (Pros.)
      (a) A foot consisting of four syllables: either two long
          and two short, -- that is, a spondee and a pyrrhic, in
          which case it is called the greater Ionic; or two
          short and two long, -- that is, a pyrrhic and a
          spondee, in which case it is called the smaller
          Ionic.
      (b) A verse or meter composed or consisting of Ionic feet.
          [1913 Webster]

   2. The Ionic dialect; as, the Homeric Ionic.
      [1913 Webster]

   3. (Print.) Ionic type.
      [1913 Webster]