Onomastics is the study of the etymology, history, and use of proper names. Etymology is the origin of a word and the historical development of its meaning.
The Maine Genealogist of Feb. 2020 Vol. 42, No.1 has an article called A Quest For Roots page 22. This is a good case study using onomastics etc. It’s also a good reminder to read articles that don’t discuss your relatives but otherwise have good ideas to help in your research.