Is "variables" even the correct term for them? Since this and arguments can be overwritten to any value, "variables" seems to fit. But is there any term that is more specific and captures the automatic, non-parameter nature of them?
A related variable is the event object sent automatically as the first parameter to any function that is bound as an event handler (at least in the W3C model). Is there a technical term for this kind of variable that is also sent automatically, but (unlike this and arguments) is only accessible if included in the function's parameter list?
I'm looking for a noun: "this and arguments are both __________."
Or perhaps an adjective: "this and arguments are ______________ variables."