What is the term for an aileron that’s also used as a ground spoiler?
The action of a ground spoiler is essentially that of a lift dumper, which also acts as an airbrake.

As far as I am aware there is no special term for an aileron which also performs this function. Several Airbus types use the technique but their literature just calls them ailerons. On the A380 at least the spoiler action is initiated by the Speed Brake lever.

Of course, "spoilerons" are not quite the same, as these are spoilers used differentially for roll control during flight.

It is not too uncommon for a device named for one function to do double duty in another. For example "landing flaps" are often also (partially) deployed for takeoff - as of course is "landing gear" - and on some older types the servo tabs also double as trim tabs.