What Is Plagiarism?: Definitions

Using parts of your assignment from another course in a new paper without citing your source.

Often, definitions of plagiarism describe it as the theft of someone's words or ideas.

At the same time, most of them aren't as clear that plagiarism is a kind of fraud. Fraud is misrepresentation that aims to gain an unfair advantage. 

Since many cases of plagiarism don't involve any actual theft, and all of them involve misrepresentation, fraud seems to be a better description of what's wrong with plagiarism.

Plagiarism is the act of representing intellectual work as something it is not -- including representing someone else's work as your own and representing your own previous work as something new.

“The action or practice of taking someone else's work, idea, etc., and passing it off as one's own; literary theft.”

("plagiarism, n." OED Online. December 2012. Oxford University Press. 3 January 2013 <http://www.oed.com/view/Entry/144939>.)

"Plagiarism is presenting another person's ideas, words, or entire works as your own" (MLA Handbook, 9th ed., 2021, p. 96).

The MLA Handbook (9th ed.) recognizes several forms of plagiarism:

• "Copying a published or unpublished text, whether deliberately or accidentally," without giving the source credit
• "Paraphrasing someone's ideas or arguments" without giving the source credit
• "Copying someone's unique wording without giving proper credit"
• Turning in a paper ... written by someone else, even if you paid for it"
• Reusing your own "ideas or phrases that you used in prior work" without citing your prior work

(MLA Handbook, 9th ed., 2021, p. 96, emphasis added)

Also see the MLA Style Center.

"Plagiarism. Researchers do not claim the words and ideas of another as their own; they give credit where credit is due (APA Ethics Code Standard 8.11, Plagiarism)."

"Just as researchers do not present the work of others as their own (plagiarism), they do not present their own previously published work as new scholarship (self-plagiarism)."

(Publication Manual of the American Psychological Association, 6th ed., pp. 15-16.)

“The act of appropriating the literary composition of another author, or excerpts, ideas, or passages therefrom, and passing the material off as one's own creation.”

("Plagiarism." West's Encyclopedia of American Law. Ed. Shirelle Phelps and Jeffrey Lehman. 2nd ed. Vol. 7. Detroit: Gale, 2005. 454-456. Gale Virtual Reference Library. Web. 3 Jan. 2013.)

“Any time I leave the impression that the words or ideas I‘ve written are mine, when actually they came from someone else, I am plagiarizing.”

(Bill Badke, “Plagiarism, eh? : How to recognize it and get it out of your life”)