I checked it out because I was curious if CEV was some international relations initialism I'd never heard of, turns out its just My Guess About What He Wants in rationalese.
Excerpt from the definition of Coherent Extrapolated Volition, or how to damage your optical nerve from too much eye rolling:
Extrapolated volition is the metaethical theory that when we ask "What is right?", then insofar as we're asking something meaningful, we're asking "What would a counterfactual idealized version of myself want* if it knew all the facts, had considered all the arguments, and had perfect self-knowledge and self-control?" (As a metaethical theory, this would make "What is right?" a mixed logical and empirical question, a function over possible states of the world.)
A very simple example of extrapolated volition might be to consider somebody who asks you to bring them orange juice from the refrigerator. You open the refrigerator and see no orange juice, but there's lemonade. You imagine that your friend would want you to bring them lemonade if they knew everything you knew about the refrigerator, so you bring them lemonade instead. On an abstract level, we can say that you "extrapolated" your friend's "volition", in other words, you took your model of their mind and decision process, or your model of their "volition", and you imagined a counterfactual version of their mind that had better information about the contents of your refrigerator, thereby "extrapolating" this volition.