The Collaborative International Dictionary of English v.0.48:

Badgerer \Badg"er*er\, n.
   1. One who badgers.
      [1913 Webster]

   2. A kind of dog used in badger baiting.
      [1913 Webster]

WordNet (r) 3.0 (2006):

badgerer
    n 1: someone who tries to embarrass you with gibes and questions
         and objections [syn: heckler, badgerer]