var f = Function; // define Function alias
var foobar = f() // write 'f' as replacement for 'function'
Arrow functions is what I was looking for (thx Xufox).
It's useful to minify your JS (thx Beejor).
To me it is also better readable and faster to code :)
So the snippet in the original question would look like:
var foobar = () => console.log("foobar"); foobar();