Dictionary of Latin synonyms?

Salvete,

can anyone recommend a (public domain) dictionary of Latin synonyms? There are quite a few out there (including the Döderlein at Project Gutenberg), and I am not quite sure which to use.

Valete,

Carolus Raeticus

There are at least three Gradus ad Parnassum on Google Books, but I couldn’t comment on the quality.

https://books.google.com/books?id=ELE2AQAAIAAJ
https://books.google.com/books?id=kmRGAQAAMAAJ
https://books.google.com/books?id=9YZOAAAAYAAJ https://books.google.com/books?id=zg9RAAAAcAAJ

Salve!

The Gradus ad Parnassum deals with poetry and is not a dictionary of synonyms. I am rather thinking along the line of one of these:

There are more out there, but I am unsure which is the most reliable one.

Vale,

Carolus Raeticus

The Wagner is a good one.

Hm, Wagner’s Lexicon Latinum is not a dictionary of Latin synonyms either.

By the way (off-topic), there is an interesting Textkit-thread about Latin-Latin dictionaries.

Vale,

Carolus Raeticus

Here is a pretty exhaustive compilation of books on Latin synonyms, with short extracts from each. The list includes those already mentioned here, as well as some other gems:
https://www.latinitium.com/blog/latinsynonyms
The work by Ogelvie, for example, is pretty interesting, especially if you are thinking of an English expression, and want guidance to choose between different Latin synonyms.