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]

Moby Thesaurus II by Grady Ward, 1.0:

151 Moby Thesaurus words for "dissatisfaction":
   Faustianism, aggravation, agreement to disagree, alienation, angst,
   anguish, annoyance, anxiety, apostasy, aversion, bad books,
   bafflement, balk, ban, betrayed hope, blackball, blackballing,
   blasted expectation, blighted hope, blow, boredom, buffet,
   cheerlessness, cold comfort, comedown, complaint, counter-culture,
   cruel disappointment, dash, dashed hope, defeat, difference,
   dim view, disaccord, disagreement, disappointment, disapprobation,
   disapproval, discomfiture, discomfort, discomposure, discontent,
   discontentedness, discontentment, disenchantment, disesteem,
   disfavor, disgruntlement, disillusion, disillusionment,
   disinclination, dislike, disliking, dismay, disparity, displeasure,
   disquiet, disrelish, disrespect, dissatisfiedness, dissension,
   dissent, dissentience, dissidence, distaste, diversity,
   divine discontent, dread, dropping out, dullness, emptiness, ennui,
   envy, exasperation, exclusion, existential woe, failure,
   fallen countenance, fiasco, fizzle, flatness, foiling,
   forlorn hope, frustration, grimness, hope deferred, ill humor,
   indignation, indisposition, inquietude, irritation, joylessness,
   lack of pleasure, letdown, low estimation, low opinion, malaise,
   minority opinion, mirage, nausea, nonagreement, nonassent,
   nonconcurrence, nonconformity, nonconsent, nongratification,
   nonsatisfaction, objection, opposition, opposure, ostracism,
   painfulness, peevishness, petulance, protest, querulousness,
   rebelliousness, recusance, recusancy, rejection, repudiation,
   resentfulness, resentment, restiveness, restlessness,
   savorlessness, secession, setback, sore disappointment, sourness,
   spleen, staleness, sulkiness, tantalization, tastelessness, tease,
   tediousness, tedium, thumbs-down, uncomfortableness, underground,
   unease, uneasiness, unfulfillment, unhappiness, unpleasure,
   unsatisfaction, variance, vexation, vexation of spirit,
   withdrawal