(abbreviation: n. n., plural nomina nuda) A nomen nudum (Latin, bare name) is a name that fails to meet the requirements for being validly published under the appropriate code of nomenclature (for instance, no published description). A nomen nudum has no official nomenclatorial standing, and does not compete for synonymy, homonymy, etc. Should a name that was previously a nomen nudum ever be validly published, its priority dates from valid publication, not from original appearance.
In these days of the internet and widespread media, nomina nuda are sometimes a significant issue (especially in vertebrate palaeontology). It is not uncommon for significant and/or interesting discoveries to be popularised in newspapers, newsgroups, etc. before their appearance in the professional literature. Any names that appear in such formats are generally nomina nuda.