To Flutter

1. (intransitive) To flap or wave quickly but irregularly.
2. (intransitive) Of a winged animal: to flap the wings without flying; to fly with a light flapping of the wings.
3. (intransitive, aerodynamics) To undergo divergent oscillations (potentially to the point of causing structural failure) due to a positive feedback loop between elastic deformation and aerodynamic forces.
4. (transitive) To cause something to flap.
5. (transitive) To drive into disorder; to throw into confusion.
6. (intransitive) To be in a state of agitation or uncertainty.
7. (intransitive, obsolete) To be frivolous.
8. (espionage, slang) To subject to a lie detector test.