At long (long, long) last, GRE Vocabulary in Practice is available for purchase on Amazon. 

The book does have lists of words and definitions, but the focus is on application rather than memorization. While there are obviously many traditional GRE vocabulary books/apps out there, this is the only one designed entirely to help you make the leap from the words to the test. Learning definitions is not the same thing as learning to work through Text Completions and Sentence Equivalences! 

When the GRE was updated in 2012, the focus of the test shifted from straight-up definitions to context-based understanding. So while traditional “hard” words are still tested (many overlapping with the old SAT pool), you’ll also find plenty of common words with second meanings (bent, tap, table), plus passages that function more like mini-logic puzzles than like traditional vocabulary questions: the answers themselves might be fairly easy, but the challenge is determining what sorts of words belong in the blanks. That means figuring out relationships without transition words to anchor you, double negatives, and challenging vocabulary in the sentences/passages themselves. 

The book gives you practice working with those challenging questions types (lots and lots of practice), and teaches you to break things down so that you don’t get tripped up.