The Collaborative International Dictionary of English v.0.48:

Burg \Burg\, n. [AS. burh, burg, cf. LL. burgus. See 1st
   Borough.]
   1. A fortified town. [Obs.]
      [1913 Webster]

   2. A borough. [Eng.] See 1st Borough.
      [1913 Webster]

WordNet (r) 3.0 (2006):

burg
    n 1: colloquial American term for a town; "I've lived in this
         burg all my life"

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "burg":
   Stadt, banlieue, boom town, borough, bourg, burgh, city,
   conurbation, crossroads, exurb, exurbia, faubourg, ghost town,
   greater city, hamlet, hick town, jerkwater town, jumping-off place,
   market town, megalopolis, metropolis, metropolitan area, mudhole,
   municipality, one-horse town, outskirts, polis, spread city,
   suburb, suburbia, town, township, urban complex, urban sprawl,
   urbs, village, ville, whistle-stop