Onomastics or onomatology is the study of proper names of all kinds and the origins of names. The word is Greek: ὀνοματολογία (from ὄνομα (ónoma) "name"). Toponymy or toponomastics, the study of place names, is one of the principal branches of onomastics. Anthroponomastics is the study of personal names.
For some cultures (and celebrities), only one name is needed to...