The Collaborative International Dictionary of English v.0.48:

Backwoods \Back"woods"\, n. pl. [Back, a. + woods.]
   The forests or partly cleared grounds on the frontiers.
   [1913 Webster]

WordNet (r) 3.0 (2006):

backwoods
    n 1: a remote and undeveloped area [syn: backwoods, back
         country, boondocks, hinterland]