onomatologist

/ˌɑnəˈmætələdʒɪst/
noun
  1. A person who studies the history and origin of proper names.
    • As an onomatologist, she helped the museum identify the origins of the artifacts' labels.
    • The local onomatologist gave a talk about how street names in the city have changed over time.
    • The onomatologist traced the name of the river back to an ancient Celtic word.