Mountweazels, Nihilartikels, and Other Fictitious Entries

Wiki:

Fictitious entries, also known as fake entries, Mountweazels, and Nihilartikels, are deliberately incorrect entries or articles in reference works such as dictionaries, encyclopedias, maps and directories. Entries in reference works normally originate from a reliable external source, but no such source exists for a fictitious entry.

Fictitious entries can be humorous hoaxes intended to be more or less quickly recognized as false by the reader or copyright traps deliberately inserted into a work to facilitate detection of copyright infringement or plagiarism.

One would typically only stumble upon a fictitious entry by chance. Some, however, are more likely to be discovered because they are closely related to a well-known fictitious subject. For example, a fictitious entry in an otherwise non-fictional reference work might define or explain a term from a work of fiction, give a biography of a character from a novel, or describe a fictional institution, without explaining that it is fictitious.

There does not appear to be any commonly used English-language term for this phenomenon. The neologism Mountweazel was coined by the The New Yorker magazine based on a fictitious entry for Lillian Virginia Mountweazel in the 1975 edition of the New Columbia Encyclopedia. Another term, Nihilartikel, is of uncertain origin, combining the Latin word nihil, "nothing" with German Artikel, "article". There is also the specific term trap street.