flaps

He has difficulty sitting still or paying attention and flaps his hands when excited or upset.

These thrust differentials are coordinated with dual flaps on the trailing edges of the stubby wings.

Parts of the engine appeared to explode at one stage, and flaps on the side of the rocket caught fire and swung from side-to-side.

They drove the truck, which had “Got Milk” signs displayed on the mud flaps, along the 5 Freeway and 101 Freeway through Studio City, Hollywood and downtown and at times went onto surface streets.

"Or the Butterfly Effect. The analogy is that if a butterfly flaps its wings in Brazil, it could have an impact on the atmosphere across northern Europe, six days later."