Source : Webster's Revised Unabridged Dictionary (1913)

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

Source : WordNet®

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