The Collaborative International Dictionary of English v.0.48:

Slash \Slash\, v. t. [imp. & p. p. Slashed; p. pr. & vb. n.
   Slashing.] [OE. slaschen, of uncertain origin; cf. OF.
   esclachier to break, esclechier, esclichier, to break, and E.
   slate, slice, slit, v. t.]
   1. To cut by striking violently and at random; to cut in long
      slits.
      [1913 Webster]

   2. To lash; to ply the whip to. [R.] --King.
      [1913 Webster]

   3. To crack or snap, as a whip. [R.] --Dr. H. More.
      [1913 Webster]

WordNet (r) 3.0 (2006):

slashing
    adj 1: as if striking with slashing blows; "his slashing demon-
           ridden cadenza"