A political upheaval in a government or nation state characterized by great change.
The removal and replacement of a government, especially by sudden violent action.
Rotation: the turning of an object around an axis.
A rotation: one complete turn of an object during rotation.
In the case of celestial bodies - the traversal of one body through an orbit around another body.
A sudden, vast change in a situation, a discipline, or the way of thinking and behaving.
A round of periodic changes, such as between the seasons of the year.
Consideration of an idea; the act of revolving something in the mind.