⟩ When gravity is the only force acting on an object the object is in what?
One answer is that it is in free-fall in a vacuum (to eliminate atmospheric drag).
Another answer is that it is in orbit around another body.
The object could be in inter-stellar space, essentially experiencing the balanced gravitational force of "everything".
If you eliminate the "middle of space" solution, the object would have to be in a state of acceleration.