NOUN (2)

1. a communication that dissuades you;

2. persuading not to do or believe something; talking someone out of a belief or an intended course of action;

The Collaborative International Dictionary of English v.0.48:

Dissuasion \Dis*sua"sion\, n. [L. dissuasio: cf. F. dissuasion.
   See Dissuade.]
   1. The act of dissuading; exhortation against a thing;
      dehortation.
      [1913 Webster]

            In spite of all the dissuasions of his friends.
                                                  --Boyle.
      [1913 Webster]

   2. A motive or consideration tending to dissuade; a
      dissuasive.
      [1913 Webster]

WordNet (r) 3.0 (2006):

dissuasion
    n 1: a communication that dissuades you
    2: persuading not to do or believe something; talking someone
       out of a belief or an intended course of action [ant:
       persuasion, suasion]