1. A state of violent disturbance and disorder: Sometimes turbulence occurs in politics or in general social conditions when times are precarious or very difficult.
2. A state of disorder, disarray, or agitation in nature: A turbulence can be an irregular motion of the atmosphere, as manifested by wind gusts and lulls, or a secondary motion of water caused by eddies in a moving flow.
3. The chaotic or unstable eddying motion in a fluid: Turbulence can be exemplified by internal motion of agitation in a liquid or cascades of water.

Avoiding excessive turbulence generated around moving objects, such as aircraft which can make their motion inefficient and difficult to control, is a major factor in aerodynamic designing.

Random fluctuations of the atmosphere often causing major deformations of its fluid flow: Atmospheric turbulence involves the mixing of warm and cold air in the atmosphere by wind, which causes clear-air turbulence that is experienced during airplane flight, as well as poor astronomical vision or the blurring of images seen through the atmosphere.