Con- is a root meaning ‘with’. It doesn’t actually mean “against”, as in pros and cons (that root would be contra). Of course, that doesn’t really help you with most words beginning with con-, since the roots that follow are not always clear-cut.
To come up with a preposterous story is to concoct a story. Let’s say you are late to an important meeting. Rather than fess up that you were simply late, you concoct this story about a six-car pile-up blocking all the lanes of a highway. Though I’d suggest telling the truth (the Twitter feed—or lack of Twitter feed on the “accident”—might reveal your concoction for what it is—a bald-faced lie).
In this case, the root is downright esoteric, since this word does not relate to con- but to the old Latin, condonare, which means to refrain from punishing. Condone, more specifically, means to turn a blind eye from actions that should be condemned because they are morally objectionable. In other words, you let something happen that you shouldn’t.
The combination of the roots con- and fer- means to bring together. Somewhat helpful for the definition of this word: to have a conference. But the more important meaning, at least for the GRE, is to bestow or grant, as in an award or certificate. A pope can confer is blessing upon a chosen few. The dean of the school can confer a diploma upon the lucky few.
Conducive means helping bring about a healthy or positive situation. The sound of waves crashing against the beach is conducive to sleep; utter quiet and a non-distracting environment are, for most people, conducive to studying. Vocabulary Wednesday—hopefully conducive to helping these words stick.
You are late to the airport, yelling at the cabbie because you think he is dyslexic–65 mph does not mean 56 mph, you feel like roaring. You finally get to the airport where they ask you for your passport. You rifle through every coat pocket, open every zipper in your luggage and then you get that feeling….that’s consternation: the unholy marriage of anxiety and dismay.
To end this story in a happy vein: you find your passport in your back pocket, but when you get to the gate, much to your consternation the flight has been delayed two hours (that is better than having to go all the way back home to get a passport).
Do you puff out your chest and walk around the room (any room!), as though you own it? Well, hopefully the answer is ‘no’, but if you answered ‘yes’, then you might be conceited: excessively proud of oneself.
A far less common definition relates to the world of art and writing. A conceit is a clever idea. In the novella Animal Farm, George Orwell satirizes Communist Russia, using animals to stand for actual people. That’s a pretty cool literary conceit. I watched a movie in which the protagonist has to kill a future version of himself. That’s definitely an intriguing conceit (the sci-fi genre is full of them!).