What does aigret or aigrette mean?
The definition of aigret and aigrette
Ai”gret, Ai*grette, n.
Etym: [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 (Zoöl.)
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.