Usually when you are looking for synonyms, you know you already know the word but you just cannot find it. So the Idea I had was to make some kind of "graph" representation of Word relationships given their meaning.
I remember finding a huge list of words with scores related to their meaning like:
Fly 1, Soar 0.9, Float 0.8.
Think, Ponder 0.9, Muse 0.8.
Which really helped, however given the different "directions" of the meaning that a word can have, this is better represented as a graph.
I finished my PhD writing with the use of said list (saddly I could never find it again), and the graph meaning idea just "went away" (lacking a better word) as I finished my degree. But the need for an efficient and quickly way to find that replacement word is still active.