"taking someone else's words or someone else's ideas without stating the sources from which you got them" (Webley, 2013); or
"the act of presenting as one's own, words or ideas taken from another source" (Edwards, 2011).
It is also considered as an act that lacks academic integrity since SMU Code of Academic Integrity defines plagiarism as using the ideas, data, or language of another without specific or proper acknowledgment.
Plagiarism occurs when:
I. Sources not cited
1) “The Ghost Writer”: The writer turns in another’s work, word-for-word, as his or her own.
2) “The Photocopy”: The writer copies significant portions of text straight from a single source, without alteration.
3) “The Potluck Paper”: The writer tries to disguise plagiarism by copying from several different sources, tweaking the sentences to make them fit together while retaining most of the original phrasing.
4) “The Poor Disguise”: Although the writer has retained the essential content of the source, he or she has altered the paper’s appearance slightly by changing key words and phrases.
5) “The Labor of Laziness”: The writer takes the time to paraphrase most of the paper from other sources and make it all fit together, instead of spending the same effort on original work.
6) “The Self-Stealer”: The writer “borrows” generously from his or her previous work, violating policies concerning the expectation of originality adopted by most academic institutions.
II. Sources Cited (but still plagiarized!)
1) “The Forgotten Footnote”: The writer mentions an author’s name for a source, but neglects to include specific information on the location of the material referenced. This often masks other forms of plagiarism by obscuring source locations.
2) “The Misinformer”: The writer provides inaccurate information regarding the sources, making it impossible to find them.
3) “The Too-Perfect Paraphrase”: The writer properly cites a source, but neglects to put in quotation marks text that has been copied word-for-word, or close to it. Although attributing the basic ideas to the source, the writer is falsely claiming original presentation and interpretation of the information.
4) “The Resourceful Citer”: The writer properly cites all sources, paraphrasing and using quotations appropriately. The catch? The paper contains almost no original work! It is sometimes difficult to spot this form of plagiarism because it looks like any other well-researched document.
5) “The Perfect Crime”: Well, we all know it doesn’t exist. In this case, the writer properly quotes and cites sources in some places, but goes on to paraphrase other arguments from those sources without citation. This way, the writer tries to pass off the paraphrased material as his or her own analysis of the cited material.
From document provided by Turnitin.com and Research Resources