Dictionary of German Synonyms
I recently bought this book Dictionary of German Synonyms for $7, well, I bought it used on Amazon.
This book really explains a lot of vocabulary and the differences really well. Though the book is aimed at B1, maybe B2 level, because of the examples only being in German and no English. The explanations are in English of course. I really needed it because Duolingo doesn't explain it at all the synonyms it throws at you, and the Discuss Sentence comments are just really hard to understand.
That books looks wonderful. As I build up my vocabulary, I find that many words are defined the same way (departure: Abfahrt, Abgang, Aurreise, Auszug, and that is just the A's) - which is frustrating because I'm not sure which word I should use. From Amazon's Look Inside option, this book really seems to clear things up. Danke!
Older book is free on archive.org: https://archive.org/details/dictionarygerma00ltdgoog