As nouns the difference between toponymy and toponym
is that toponymy is lexicological study of place names; a branch of onomastics while toponym is toponym, place name.
toponymy
English
Noun
(-)
lexicological study of place names; a branch of onomastics
Synonyms
* toponomastics
Derived terms
* toponym
* toponymic
* toponymist
Hypernyms
* onomastics
toponym
English
Noun
(
en noun)
A placename.
A word derived from the name of a place.
Synonyms
* (place name) (l), (l)