The Collaborative International Dictionary of English v.0.48:

Frustration \Frus*tra"tion\, n. [L. frustratio: cf. OF.
   frustration.]
   The act of frustrating; disappointment; defeat; as, the
   frustration of one's designs.
   [1913 Webster]

WordNet (r) 3.0 (2006):

frustration
    n 1: the feeling that accompanies an experience of being
         thwarted in attaining your goals [syn: frustration,
         defeat]
    2: an act of hindering someone's plans or efforts [syn:
       frustration, thwarting, foiling]
    3: a feeling of annoyance at being hindered or criticized; "her
       constant complaints were the main source of his frustration"

Moby Thesaurus II by Grady Ward, 1.0:

76 Moby Thesaurus words for "frustration":
   ambivalence, ambivalence of impulse, annulment, bafflement, balk,
   balking, betrayed hope, blasted expectation, blighted hope, blow,
   buck-passing, buffet, cancellation, check, checkmate,
   circumvention, comedown, conflict, confounding, confusion,
   counterbalancing, cruel disappointment, dash, dashed hope,
   decompensation, defeat, disappointment, discomfiture,
   disconcertion, disillusionment, dissatisfaction, elusion,
   emotional shock, evasion, external frustration, failure,
   fallen countenance, fiasco, fizzle, foil, foiling, forlorn hope,
   getting around, getting round, hope deferred, invalidation,
   letdown, mental shock, mirage, neutralization, nullification,
   offsetting, outguessing, outmaneuvering, outwitting,
   passing the buck, psychological stress, rebuff, repulse, reversal,
   reverse, rout, setback, sore disappointment, stress, tantalization,
   tease, the runaround, the slip, thwarting, trauma, traumatism,
   undoing, upset, vitiation, voiding