Source : Webster's Revised Unabridged Dictionary (1913)

Plagiarism \Pla"gia*rism\, n. [Cf. F. plagiarisme.]
   1. The act or practice of plagiarizing.

   2. That which plagiarized.

Source : WordNet®

plagiarism
     n 1: a piece of writing that has been copied from someone else
          and is presented as being your own work
     2: the act of plagiarizing; taking someone's words or ideas as
        if they were your own [syn: {plagiarization}, {plagiarisation},
         {piracy}]