The GRE has its spindly fingers on the pulse of colloquial English. It knows very well the words that we often misuse while speaking, and it has a fondness for peppering the verbal section with these words. So, let me disabuse you of the colloquial definitions of these words, lest you get caught on test day.
If you are sociable, you are talkative, right? Well, not exactly. To be gregarious is to be likely to socialize with others. A good synonym is flocking, like what birds do. But, just as birds do not talk to one another outside of a Pixar flick, people can hang out with each other and not necessarily have to chat. Therefore, do not confuse gregarious with garrulous, which means talkative.
You may think you’ve heard someone exclaim, what an ingenuous plan! But, it’s actually an ingenious plan. To be ingenuous is to be naïve and innocent. So, if you are likely to go along with a devious plan, whether or not it is ingenious, you are ingenuous.
Peruse means to read very carefully. Unfortunately, the colloquial usage not only ignores this definition, but goes so far as to flip this definition on its head. Now, peruse means to read over quickly. So, make sure to remember this definition, and, if necessary, peruse the definition.
To disabuse is not the opposite of abuse (which would be a strange word to have an opposite for in the first place). To disabuse is to persuade somebody that his/her belief is not valid. Often, disabuse goes together with the word notion:
As a child, I was quickly disabused of the notion that Santa Claus was a rotund benefactor of infinite largess, when I saw my mother diligently wrapping presents and storing them under our Christmas tree.
When you poke your nose in somebody else’s business, you are being meddlesome. If you are mettlesome, on the other hand, you are filled with mettle (no, not the hard stuff), which means courage or valor. A soldier on the battlefield is mettlesome when he runs into enemy fire to save a comrade.