The Collaborative International Dictionary of English v.0.48:

Uprising \Up*ris"ing\, n.
   1. Act of rising; also, a steep place; an ascent. "The steep
      uprising of the hill." --Shak.
      [1913 Webster]

   2. An insurrection; a popular revolt. --J. P. Peters.
      [1913 Webster]

WordNet (r) 3.0 (2006):

uprising
    n 1: organized opposition to authority; a conflict in which one
         faction tries to wrest control from another [syn:
         rebellion, insurrection, revolt, rising,
         uprising]