Plagiarism is passing off someone else's writing or ideas as your own. Accused of plagiarism, plagiarism checker, blatant plagiarism.
It is an offence against honesty rather than against the law — copyright is the legal matter, and the two overlap without being the same, since you can plagiarise work that is out of copyright. Universities treat it as misconduct. Note that the Latin plagiarius meant a kidnapper, which is a striking origin.
1nounplagiarismPassing off someone else's writing or ideas as your own.
“The student was expelled for plagiarism after copying his essay from a website.”
plagiarism is a form of dishonesty.
From plagiary + -ism.
Etymology from Wiktionary, CC BY-SA