Putting a little english on the thread.

Spin put on a ball, usually but not always a billiard ball, is called "english" (always lower case). The British call the same effect "side," because it is accomplished by striking the ball slightly off-centre, thus imparting the spin.

The actions that the player makes to cause the ball to spin -- the extra gestures, physical effort and "oomph", we know as "body English" because such physical gestures (waving your hands, hopping up and down, etc.) are sometimes used to boost the expressive effect of our spoken English.

Actual English people, of course, are possibly the least likely people on Earth to employ "body English" while speaking, but that's another story.

The above is approximately taken from Word Detective.