Onomastics refers to the broad science of naming be it toponomastics (the study of place names) or anthroponomastics (the study of personal names). Why onamastics? It’s useful in data mining. Onomasticians study the process of naming of persons and places in myth, literature and film too.
There are names of places that are lived in and not and names for streets, roads and water bodies. Cities are named after kings or politicians, planets are named after mythical characters, and people are named after their parents. Naming conventions differ from country to country- sometimes the family name appears first as in Chinese or the place name appears first as it does in some Keralite names. Naming can be a personal business; in many cultures around the world naming ceremonies exist. Naming can also be a political exercise especially when the names of cities are changed.
I dug around to find how this word has been used and it isn’t used much at all unless you are talking linguistics. Except here in this article which describes Charles Dickens’s prowess when it comes to naming his characters.
“Allow me to introduce Mr Plornishmaroontigoonter. Lord Podsnap, Count Smorltork, and Sir Clupkins Clogwog. Not to mention the dowager Lady Snuphanuph. As for Serjeant Buzfuz, Miss Snevellicci, Mrs. Wrymug, and the Porkenhams… who the dickens are all these people? Why do they have such weird names?
They are the best of names, they are the worst of names, from an age of onomastic wisdom and hypocoristic foolishness, an epoch of… well you get the picture. You may recognize this raggle-taggle cast of minor characters, in all their rich variety, as stemming from the fevered imaginings of one Charles Dickens.”