Most commercial airline autopilots in use today could land the plane on auto if desired by the flight crew, so no, they don’t “just maintains a heading and an altitude”.
I think we all know that such technology exists. That is why I specifically said "in the traditional sense", to point out that I'm talking about what the word was invented for.
Autopilot can refer to everything between a "wing leveler", and a full-on automated landing system. So no, even in aviation there is no standard definition of what autopilot does.
