Pronunciation: (rev"u-lOO'shun),[key] —n. 1. an overthrow or repudiation and the thorough replacement of an established government or political system by the people governed.
2. Sociol.a radical and pervasive change in society and the social structure, esp. one made suddenly and often accompanied by violence. Cf. social evolution. 3. a sudden, complete or marked change in something: the present revolution in church architecture. 4. a procedure or course, as if in a circuit, back to a starting point.
5. a single turn of this kind.
6. Mech. a. a turning round or rotating, as on an axis.
b. a moving in a circular or curving course, as about a central point.
c. a single cycle in such a course.
7. Astron. a. (not in technical use) rotation (def. 2).
b. the orbiting of one heavenly body around another.
c. a single course of such movement.
8. a round or cycle of events in time or a recurring period of time.
9. Geol.a time of worldwide orogeny and mountain-building.