Body:getAngularVelocity
Get the angular velocity of the Body.

The angular velocity is the ''rate of change of angle over time''.

It is changed in World:update by applying torques, off centre forces/impulses, and angular damping. It can be set directly with Body:setAngularVelocity.

If you need the ''rate of change of position over time'', use Body:getLinearVelocity.
w = Body:getAngularVelocity()
w number The angular velocity in radians/second.