The Collaborative International Dictionary of English v.0.48:

Heron \Her"on\, n. [OE. heiroun, heroun, heron, hern, OF.
   hairon, F. h['e]ron, OHG. heigir; cf. Icel. hegri, Dan.
   heire, Sw. h[aum]ger, and also G. h[aum]her jay, jackdaw,
   OHG. hehara, higere, woodpecker, magpie, D. reiger heron, G.
   reiher, AS. hr[=a]gra. Cf. Aigret, Egret.] (Zool.)
   Any wading bird of the genus Ardea and allied genera, of
   the family Ardeid[ae]. The herons have a long, sharp bill,
   and long legs and toes, with the claw of the middle toe
   toothed. The common European heron (Ardea cinerea) is
   remarkable for its directly ascending flight, and was
   formerly hunted with the larger falcons.
   [1913 Webster]

   Note: There are several common American species; as, the
         great blue heron (Ardea herodias); the little blue
         (Ardea c[oe]rulea); the green (Ardea virescens);
         the snowy (Ardea candidissima); the night heron or
         qua-bird (Nycticorax nycticorax). The plumed herons
         are called egrets.
         [1913 Webster]

   Heron's bill (Bot.), a plant of the genus Erodium; -- so
      called from the fancied resemblance of the fruit to the
      head and beak of the heron.
      [1913 Webster]