Definitions
1.nounThe state or fact of being turbulent or agitated; tempestuousness, disturbance.
2.nounDisturbance in a gas or fluid, characterized by evidence of internal motion or unrest.
3.nounSpecifically, a state of agitation or disturbance in the air which is disruptive to an aircraft.
4.nounAn instance or type of such state or disturbance.