Definitions for "Onomastics"
(a) The science that has as its object the study of names. (b) The activity or process of giving names.
the branch of lexicology that studies the forms and origins of proper names
Onomastics or onomatology is the study of proper names of all kinds and the origins of names. The word is derived from the Greek word ὄνομα (onoma), meaning name. Toponymy or toponomastics, the study of place names, is one of the principal branches of onomastics.