Noun: Onomastics (ah-nuh-MAS-tiks)
1: The science or study of the origins and forms or words used in a specialized field, or of proper names of persons or places.
2. The system underlying the formation and use of words, especially proper names or of words used in a specialized field.
Example sentence: As a student of onomastics, Gloria liked to keep track of the most popular baby names across generations.