[kgeist]

Interesting:

  Russia - Europe = Putin
  Ukraine + Putin = Russia
  Putin - Stalin = Bush
  Stalin - purge = Lenin

That means Bush = Ukraine+Putin-Europe-Lenin-purge.

However, the site gives Bush -4%, second best option (best is -2%, "fleet ballistic missile submarine", not sure what negative numbers mean).

[nxa]

My interpretation of negative numbers is that no "synonym" was found (no vector pointing in the same direction), and that the closest expression on record is something with an opposite meaning (pointing in reverse direction), so I'd say that's an antonym.