With greater emphasis on vocabulary in context, the Revised GRE demands a new approach to learning vocabulary. Gone are the days of simply relying on vocabulary lists and flashcards. You’ll now have to be far more creative than that if you hope to learn words in context.
To really make sure you understand a word, and are not just reciting a definition, you must have a strong understanding of how that word functions in a sentence. Finding words embedded in a sentence requires you to be proactive, using the web as much as possible.
Taken together, this approach of learning vocabulary will make you a vocabulary expert.

1. Read with an online dictionary and Flashcards.

Let’s say you encounter the following five words while reading an article in The New York Times. Which of the following can be a GRE word?
Sporadic
Incumbent
Robust
Echelon
Bemoan
The answer? Well, all of them. See, there is no definitive word list of GRE vocabulary. ETS chooses words that commonly circulate in periodicals and journals. ETS does not scour Barron’s 3500 Word list looking for inspiration. The way to approach vocabulary is to think that if you do not know a word, then it is fair game for the GRE. In fact, you want to be aggressive – every word you do not know could be a vocabulary question on the GRE.
Being a word addict goes a little bit further than just looking up a word. Once you have a definition for a word, you should get a sense of the likelihood that word will show up on the test. Basically you have to build a 3D word model in your mind .

If you believe the word is a high-frequency word, you can crosscheck it in books, such as any of those I named earlier, or on quizlet.com. Those words tend to be more likely to show up on the GRE, but even if echelon doesn’t appear in these sources, that doesn’t mean it won’t show up on the Revised GRE. The likelihood of it doing so is just less.
If you feel you will forget the definition, write it down on a blank flashcard or enter it into quizlet.com.

2. Find Example Sentences

Wordnik.com is a great Internet resource with example sentences. And these aren’t example sentences like the following: she was very reticent and never spoke unless called on. Rather, you will have example sentences taken from reliable and respected resources. The writing will be at the same level as that encountered on the New GRE. Remember, reading vocabulary words embedded in sentences will help you become more familiar with that word at a deeper level.

3. Notice Roots or Backstories

Sometimes, words have an interesting etymology, or backstory. For instance, supercilious refers to the hair in your eyebrows, cilia. When you raise your eyebrows (super = the root for above), you essentially are condescending or looking down at somebody. What is important to remember with roots is that you have to be very careful memorizing them proactively—meaning, do not memorize cilia- and then apply it to conciliate (the words are totally unrelated).

4. Find and Relate similar Words

Word grouping can still be very helpful if done judiciously– and notice, BTW it is grouping, not lumping. So, notice how words are similar and different. For instance, do not think that condemn and berate are the same word because they can be put under the larger heading, showing disapproval for (condemn is to express extreme disapproval for, usually in public; berate is to scold a person at length).
So, if you think two words you’ve learnt are similar, let’s say laconic and reticent, then look them up in a dictionary (a good word addict always has his or her dictionary open, whether it be on your desktop, on-line, or in front of you in corporeal form).

5. Always Revisit Words

My only caveat to this method is that it is not very practical if you are cramming for the GRE. And by cramming, I mean any amount of time less than two weeks—being a word detective pays dividends over larger periods of time. However, do not constantly be learning new words without returning to older words you’ve learnt. Flashcards (and quizlet.com) make this easier to do.
The best part of reading is when you notice words you’ve come across that you’ve read earlier. You might instantly recognize the word and be able to define it. Or, you may take a little longer, hem and haw, trying to pin down the exact definition. And doing so is fine. That’s your brain trying to retract that definition from long-term memory. This entire process will make recalling or recognizing the word much easier in the future.

Conclusion

Learning vocabulary takes a proactive approach of reading, defining, and crosschecking.
Make sure you not only learn the definition of a word but how that word functions in complex sentences.