onomastics

noun (used with a singular verb)

1. the study of the origin, history, and use of proper names.

noun

1. (functioning as singular) the study of proper names, esp of their origins
2. (functioning as singular or plural) a systematization of the facts about how proper names are formed in a given language

n.“scientific study of names and naming,” 1936, from onomastic; also see -ics.