turbulence

rough or unsteady movement of air or water

Example Sentences:

There was turbulence during the flight, so I had to wear my seatbelt.

Airplane Pilot: Hello, this is your Captain speaking. I am going to turn on the seatbelt sign, as we are experiencing some turbulence. Please sit down.

Media and Links:

Severe Turbulence – July 20 2010