for the joy of new words, some definitions:
odonym = street name "Oak Street"
odonymy = the study of street names
toponym = place name "One Tree Hill"
toponymy = the study of place names
metonym = a word used in place of something closely associated "Washington" for "United States Government"
metonymy = the use of a word or phrase in place of something closely associated
onomastics = science of studying names
allonym = each of two or more toponyms applied to a single geographic feature "Istanbul" and "Constantinople"
anthroponym = personal name given to a place "Washington D.C." or "Lincoln, NE"
endonym = name of a geographical feature in the language of that area "Beijing" and not "Peking"
eponym = name of a person or group of person after or for whom a place is named "Seattle" for Chief Seattle
epotoponym = toponym that supplies the origin of a common noun "Jerez" for sherry; "Olympia" for the Olympics
exonym = name in a specific language for a geographic feature situated outside of the area where that language has official status Warsaw is the English exonym for Warszawa; Londres is French for London
gazetteer = list of toponyms arranged in alphabetic or other sequential order, with an indication of their location and preferably including variant names
hydronym = name applied to a (hydrographic) feature consisting of water the Danube; the Indian Ocean
oronym = name applied to a feature of topographic elevation such as a mountain or a hill "Sierra Madre"