(aviation) The disturbances formed in the atmosphere behind an aircraft passing through the air, consisting primarily of a combination of wake vortices and jet blast or prop wash.

The erratic movement of air masses in the absence of any visual cues, especially such movement that causes unexpected turbulence to an aircraft.

plural of clear-air turbulence

(physics) A form of irregular viscous flow in which the velocity and pressure of the fluid fluctuates at random in both time and space,

plural of turbulent flow