Looking for a good name for that sort of pattern, and more specifically how to name the `sortBy` function to best convey what it does.

function-factory.js

function sortBy(prop) {
    return function(a, b) {
        return a[prop].localeCompare(b[prop]);
    }
}

[
    { foo: "some text", bar: "other text" },
    { foo: "hello",     bar: "world" },
    { foo: "More text", bar: "MOAR" }
].sort(sortBy('foo'));

It's just a higher-order function. Being a closure would imply some context to be captured, but here you're passing it to the function so it's not happening.

About naming the function, I believe that sortBy conveys the right information and would not change it.