Obviously, it means many things to many people. This definition might be the most universal, though:
The same applies when the cueball and object ball are close to each other, even with a relatively soft stroke, though I'm not sure many would refer to hitting above center as "force follow" in this case. But I think it should be considered equivalent, per Wille Hoppe's definition cited above.
Why the topspin is called for (i.e., what you're trying to accomplish), should probably not be a part of the definition since there are several applications, as has already been noted.
Jim
At typical distances separating the cueball and object ball, striking centerball with a soft or even medium speed stroke will, as we all know, result in the cueball acquiring a lot of topspin from cloth friction along the way to the object ball. In fact, it'll often be fully rolling by the time it reaches it. But with a hard stroke and resultant fast cueball speed, friction doesn't have that much time to act, and thus, not much topspin develops "naturally." Therefore, if significant topspin is desired, you have to 'force' the issue by hitting well above center.Basically it's any time that you use follow and hit relatively hard...
The same applies when the cueball and object ball are close to each other, even with a relatively soft stroke, though I'm not sure many would refer to hitting above center as "force follow" in this case. But I think it should be considered equivalent, per Wille Hoppe's definition cited above.
Why the topspin is called for (i.e., what you're trying to accomplish), should probably not be a part of the definition since there are several applications, as has already been noted.
Jim