1.  dirndl(n = noun.artifact) - a full skirt with a gathered waistband;
is a kind of gathered skirt

2.  dirndl(n = noun.artifact) - a dress with a tight bodice and full skirt;
is a kind of dress, frock

dirndl, n.
1 a woman's dress styled in imitation of Alpine peasant costume, with close-fitting bodice, tight waistband, and full skirt.
2 a full skirt of this kind.

Etymology:
G dial., dimin. of Dirne girl