nomenclator

/ˈnoʊmənˌkleɪtər/
noun
  1. A person who assigns names to things, especially in scientific or technical fields.
    • The ancient Roman nomenclator would whisper the names of guests to the host.
    • As a nomenclator, she helped standardize the names of chemical compounds.
    • The nomenclator for the botanical society named the new flower species.
  2. A book or list of names or terms, often with explanations; a glossary or directory.
    • He kept a nomenclator of clients' names for his business.
    • The medieval nomenclator listed all the herbs used in medicine.
    • The scientist consulted a nomenclator of bird species.