The Collaborative International Dictionary of English v.0.48:

Dissatisfaction \Dis*sat`is*fac"tion\, n.
   The state of being dissatisfied, unsatisfied, or
   discontented; uneasiness proceeding from the want of
   gratification, or from disappointed wishes and expectations.
   [1913 Webster]

         The ambitious man has little happiness, but is subject
         to much uneasiness and dissatisfaction.  --Addison.

   Syn: Discontent; discontentment; displeasure; disapprobation;
        distaste; dislike.
        [1913 Webster]

WordNet (r) 3.0 (2006):

dissatisfaction
    n 1: the feeling of being displeased and discontent; "he was
         never slow to express his dissatisfaction with the service
         he received" [ant: satisfaction]