While plagiarism can be copyright infringement and an accusation of plagiarism can arise out of the same activities, it is not necessarily copyright infringement. Plagiarism is taking someone else’s ideas without attribution. So for example in this glossary, the author willingly admits to having looked at many other legal dictionaries and glossaries to see what their authors thought important to explain, but not to copying any expression in those glossaries. Language from statutory definitions and court decisions may also have been copied or paraphrased – but since this language is “public domain” there is no copyright infringement. To the extent that another writer considering the term important may have inspired the existence of an entry, or because it is in the public domain, that is possibly plagiarism but not copyright infringement.