The Collaborative International Dictionary of English v.0.48:

Prorogue \Pro*rogue"\, v. t. [imp. & p. p. Prorogued; p. pr. &
   vb. n. Proroguing.] [F. proroger, L. prorogare, prorogatum;
   pro forward + rogare to ask, to ask one for his opinion or
   vote, or about a law. See Rogation.]
   1. To protract; to prolong; to extend. [Obs.]
      [1913 Webster]

            He prorogued his government.          --Dryden.
      [1913 Webster]

   2. To defer; to delay; to postpone; as, to proroguedeath; to
      prorogue a marriage. --Shak.
      [1913 Webster]

   3. To end the session of a parliament by an order of the
      sovereign, thus deferring its business.
      [1913 Webster]

            Parliament was prorogued to [meet at] Westminster.
                                                  --Bp. Hall.
      [1913 Webster]

            The Parliament was again prorogued to a distant day.
                                                  --Macaulay.
      [1913 Webster]

   Syn: To adjourn; postpone; defer. See Adjourn.
        [1913 Webster]

WordNet (r) 3.0 (2006):

prorogue
    v 1: hold back to a later time; "let's postpone the exam" [syn:
         postpone, prorogue, hold over, put over, table,
         shelve, set back, defer, remit, put off]
    2: adjourn by royal prerogative; without dissolving the
       legislative body