Hannay angle

In classical mechanics, the Hannay angle is a mechanics analogue of the whirling geometric phase (or Berry phase). It was named after John Hannay of the University of Bristol, UK. Hannay first described the angle in 1985, extending the ideas of the recently formalized Berry phase to classical mechanics.
Example.
The Foucault pendulum is an example from classical mechanics that is sometimes used to illustrate the Berry phase.