I understand the meaning of "synonym", I'm just not sure of its usage, in particular the correct preposition follows it. From 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. [![enter image description here][1]][1] Does this mean the same thing as the quotation? > Cool is not **a synonym of** all things good. [1]: https://i.sstatic.net/ivRCC.png