I understand the meaning of "synonym", I'm just not sure of its usage, in particular the correct preposition follows it.
From Cambridge DictionaryFrom Cambridge Dictionary
Cool is not a synonym for all things good.
Which indicates "a synonym for" is a correct use.
Ngram Viewers shows "a synonym of" could also be a correct use.
Does this mean the same thing as the quotation?
Cool is not a synonym of all things good.