Silly Gimbal head question

So, I have a Gimbal as well as a ball head. I got to wondering what the definition of gimbal was so I found the following:

​"A gimbal is a pivoted support that allows the rotation of an object about a single axis"

Isn't that what my ballhead also does? Or is the defining word here "pivotal"?

Silly question but this is what I think about when I should clearly be thinking about more pertinent things. gary

Ballhead allows rotation/movement in all three axes. A gimbal allows rotation in only one axis. A 'gimbal head' generally allows rotation of pitch only, although it's often combined with a base that rotates for yaw (and a tripod collar can provide roll).

http://www.mediachance.com/hdri/help/clip0015.jpg