The Collaborative International Dictionary of English v.0.48:

Brandish \Bran"dish\, v. t. [imp. & p. p. Brandished; p. pr. &
   vb. n. Brandishing.] [OE. braundisen, F. brandir, fr. brand
   a sword, fr. OHG. brant brand. See Brand, n.]
   1. To move or wave, as a weapon; to raise and move in various
      directions; to shake or flourish.
      [1913 Webster]

            The quivering lance which he brandished bright.
                                                  --Drake.
      [1913 Webster]

   2. To play with; to flourish; as, to brandish syllogisms.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Brandish \Bran"dish\, n.
   A flourish, as with a weapon, whip, etc. "Brandishes of the
   fan." --Tailer.
   [1913 Webster]

WordNet (r) 3.0 (2006):

brandish
    n 1: the act of waving [syn: flourish, brandish]
    v 1: move or swing back and forth; "She waved her gun" [syn:
         brandish, flourish, wave]
    2: exhibit aggressively; "brandish a sword"