"When you wanted to trace all synonyms Google knows for a word." You can also put the tilde ("~") character ahead of the word if you want to include variants and synonyms of that word.

Yes, exactly! So if you wanted to find all synonyms of a word, you can do this:

~search -search

... then check the word in bold, and exclude it again ...

~search -search -finder

... and so on, like ...
~search -search -finder -database -listings -searching

... and often, you'd run into the 10-word limit here very fast.