I have my gmat on the 17th of December. I want to know if spending time on vocabulary now is worthwhile.
That depends. Are you a native English speaker? If so, you probably won't have trouble with any/many of the words on the GMAT, save for the technical jargon in the science passages for reading comp. Unlike the GRE, the GMAT (fortunately) does not test bizarre vocabulary words.
If you aren't a native English speaker and you have trouble with basic English vocab, then yes, you might want to spend some time reviewing your English words.
