“In-” is my poster child for why I don’t care for roots. Sure, roots can help you here and there, but most of the time words you’ll encounter on the GRE have roots that are very esoteric and only appear in one or two roots. With “in-“, you are even on slipperier ground: it can either mean “into/towards” or “not”. There’s no way of telling which. Therefore, you are better off memorizing the word.
“In-” is indubitably a diabolical root. If you haven’t guessed from context, indubitably means without doubt. The Earth revolves around the Sun, a mile is longer than a kilometer, and the fact that that dress is black and blue are all indubitable (at least to most people!).
Not only do you have to contend with “in-” but the “grat”, which might lead you to think that this word has something to do with gratitude. It doesn’t. The “grat” comes from an Italian word that doesn’t pop up anywhere else in the GRE lexicon.
So what does ingratiate mean? To try to make friends and be liked through flattery when you are the new person or when you have some hidden agenda. Social climbers usually ingratiate themselves whenever people of higher social standing are in the room. “Did I mention my new condo in the French Riviera…it’s probably nothing like your yacht though, I’m sure”. That kind of chatter can be grating, which is maybe a good way to remember ingratiate. Though it should be noted that “grating” comes from old German (quite the etymological stew we have cooking here!)
This word comes from the Latin “to nod towards”, which makes sense, considering its meaning. An innuendo is an oblique or subtle remark that typically pokes fun at or disparages something. If I am in the same room with a person trying to ingratiate themselves, I could make an innuendo about how some people only open their mouths if they think they can get something out of it.
To charge someone guilty of a crime is to indict them. The word doesn’t have much of an application outside of the courtroom, but it could be a good distractor in a test question. A similar looking, but very different word, is indite, which means to write. This is a pretty archaic word, but I thought I’d throw it in there anyway.
Somebody who is disobedient and goes out of his or her way to defy authority is insubordinate. The word does not have a positive connotation the way that “rebel” or “protestor” might. If somebody is being insubordinate, that person is being unruly and rebellious for the sake of being doing so.