The Collaborative International Dictionary of English v.0.48:

paradiddle \paradiddle\ n.
   The sound of a drum (especially a snare drum) beaten rapidly
   and continuously.

   Syn: roll, drum roll.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

paradiddle
    n 1: the sound of a drum (especially a snare drum) beaten
         rapidly and continuously [syn: paradiddle, roll, drum
         roll]