Absolutes are concepts that either are or aren’t—no middle ground. Perhaps the most well known use of an absolute is a quip, “she’s a little bit pregnant.” Pregnancy is a thing where either you are or you aren’t. I mentioned an absolute, unique, some time ago. Here’s another that I just ran into. Misused in the example, of course:
And second, this engine might one day push spacecraft to velocities sufficient enough to open the Solar System to human exploration.
The article, from Ars Technica, is pretty interesting, about a new type of rocket engine. (Go to the article to find out what the first thing is.) Sufficient is an absolute. Something is either sufficient or it isn’t. You can say something like “almost sufficient,” but that’s the same as “not sufficient.” So the phrase “sufficient enough” is a solecism. Don’t use it.
That earlier post, about absolutes, mentions several others. Words that are absolutes might be tricky, but they aren’t unique!