You make a powerful point about cons cells being a more fundamental type than lists. I think if we really wanted english language words to describe the parts of a cons, "left" and "right" would be appropriate for what a cons is in isolation, but would unfortunately be meaningful only if you're using conses to represent binary trees. The beauty of a cons is that it's the smallest possible structure out of which one can build arbitrarily larger composites. And I'm not sure how valuable metaphors from the physical world are when contemplating abstractions - a cons is another degree removed from everyday reality than windows, buttons, dialogs, tabs, and menus are.
