The Collaborative International Dictionary of English v.0.48:

knickers \knick"ers\, n. pl.
   1. The name for a style of loose-fitting short trousers,
      gathered in and ending at the knees; smallclothes; called
      also knickerbockers.

   Syn: breeches, knee breeches, knee pants, knickerbockers.
        [1913 Webster + WordNet 1.5]

   2. Underpants, especially of women; panties. [British]

   Syn: bloomers, pants, drawers.
        [PJC + WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

Knickerbockers \Knick"er*bock`ers\, n. pl.
   The name for a style of short breeches; smallclothes; called
   also knickers.
   [1913 Webster]

WordNet (r) 3.0 (2006):

knickers
    n 1: trousers ending above the knee [syn: breeches, knee
         breeches, knee pants, knickerbockers, knickers]
    2: underpants worn by women; "she was afraid that her bloomers
       might have been showing" [syn: bloomers, pants,
       drawers, knickers]