Source : Webster's Revised Unabridged Dictionary (1913)

Aigret \Ai"gret\, Aigrette \Ai*grette\, n. [F., a sort of white
   heron, with a tuft of feathers on its head; a tuft of
   feathers; dim. of the same word as heron. See {Heron}, and
   cf. {Egret}, {Egrette}.]
   1. (Zo["o]l.) The small white European heron. See {Egret}.

   2. A plume or tuft for the head composed of feathers, or of
      gems, etc. --Prescott.

   3. A tuft like that of the egret. (Bot.) A feathery crown of
      seed; egret; as, the aigrette or down of the dandelion or
      the thistle.

Source : WordNet®

aigrette
     n : a long plume (especially one of egret feathers) worn on a
         hat or a piece of jewelry in the shape of a plume [syn: {aigret}]