Plagariasm
Plagariasm is (defined by Meriam Webster Online) "to steal or pass off (the ideas or words of another) as one's own; use without crediting the source. For example, if you were to take a cookie from the cookie jar at home without telling anyone, this would be similar to plagariasm. Sometimes, you can use a simple phrase (or cookies) and it can pass by without Ms. Miller knowing. However, you know that stealing is wrong and there will be consequences.