The Collaborative International Dictionary of English v.0.48:

Flounce \Flounce\, n.
   The act of floucing; a sudden, jerking motion of the body.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Flounce \Flounce\, n. [Cf. G. flaus, flausch, a tuft of wool or
   hair; akin to vliess, E. fleece; or perh. corrupted fr.
   rounce.]
   An ornamental appendage to the skirt of a woman's dress,
   consisting of a strip gathered and sewed on by its upper edge
   around the skirt, and left hanging.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Flounce \Flounce\, v. t.
   To deck with a flounce or flounces; as, to flounce a
   petticoat or a frock.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Flounce \Flounce\, v. i. [imp. & p. p. Flounced (flounst); p.
   pr. & vb. n. Flouncing.] [Cf. OSw. flunsa to immerge.]
   To throw the limbs and body one way and the other; to spring,
   turn, or twist with sudden effort or violence; to struggle,
   as a horse in mire; to flounder; to throw one's self with a
   jerk or spasm, often as in displeasure.
   [1913 Webster]

         To flutter and flounce will do nothing but batter and
         bruise us.                               --Barrow.
   [1913 Webster]

         With his broad fins and forky tail he laves
         The rising sirge, and flounces in the waves. --Addison.
   [1913 Webster]

WordNet (r) 3.0 (2006):

flounce
    n 1: a strip of pleated material used as a decoration or a trim
         [syn: frill, flounce, ruffle, furbelow]
    2: the act of walking with exaggerated jerky motions
    v 1: walk emphatically