University of Dayton Undergraduate Bulletin's definition of Plagiarism
B. Committing Plagiarism and Using False Citations
Plagiarism consists of quoting directly from any source of material without appropriately citing the source and identifying the quoted material; knowingly citing an incorrect source; or using ideas (i.e. material other than information that is common knowledge) from any source of material without citing the source and identifying the borrowed material. Students are responsible for educating themselves as to the proper mode of attributing credit in any course or field. Faculty may use various methods to assess the originality of students' work, such as plagiarism detection software.
Source: University of Dayton Undergraduate Bulletin
Graduate Students: see the University of Dayton Graduate Bulletin