Person crossing out artist's signature to claim work as their own Hand: https://pixabay.com/en/quality-hand-write-pen-signature-500958/ (public domain)
The UC Student Code of Conduct defines plagiarism as:
•Submitting another’s published or unpublished work in whole, in part or in paraphrase, as one’s own without fully and properly crediting the author with footnotes, quotation marks, citations, or bibliographic references.
•Submitting as one’s own original work, material obtained from an individual, agency, or the internet without reference to the person, agency or webpage as the source of the material.
•Submitting as one’s own original work material that has been produced through unacknowledged collaboration with others without release in writing from collaborators
•Submitting one’s own previously written or oral work without modification and instructor permission.