Some people spell it as “hox“.
Hocks refers to the position where your knees are hooked on the hoop. It’s a very essential pose and a common transition between others. Typically you also pass through hocks as you mount the hoop through either pike or straddle.
When you first try it, it might feel a bit scary, but the pose is accessible to most beginners.
A more advanced variation is single leg hocks. As the name states, this means all your weight is on one knee while the other leg is off the hoop. Most people aren’t able to do it frm the beginning, and the strength (and pain tolerance) for this can take a while to build up to.