The second edition of the Oxford English Dictionary defines plagiarism as "...the wrongful appropriation or purloining, and publication as one's own, of the ideas, or the expression of the ideas (literary, artistic, musical, mechanical, etc.) of another." (Vol. XI, p. 947)
How does this apply to you? The sites below define plagiarism, give examples of it, and provide tips on how to avoid this in your writing.