Rĕv'o-lū'tion, n.

n. [Fr. révolution, Pr. revolucio, Sp. revolucion, It. revoluzione, rivoluzione, Lat. revolutio. See REVOLVE.]

1. The act of revolving, or turning round on an axis or a center; the motion of a body round a fixed point; rotation; as, the revolution of a wheel, of a top, and the like.
2. Return to a point before occupied; rolling back; return.

That fear Comes thundering back, with dreadful revolution, On my defenseless head. Milton. 3. The space measured by the regular return of a revolving body; the period made by the regular recurrence of a measure of time, or by a succession of similar events. “The short revolution of a day.” Dryden.

4. A total or radical change.
5. (Astron.) (a.) The motion of any body, as a planet or satellite, in a curved line or orbit, until it returns to the same point again, designated as the annual, anomalistic, nodical, sidereal, or tropical revolution, according as the point of return or completion has a fixed relation to the year, the anomaly, the nodes, the stars, or the tropics. (b.) The motion or the period of rotation of a heavenly body about its axis.

☞ The term is applied, appropriately, to the motion of one body round another, as a planet round the sun, rather than to that of a single body, as a planet about its own axis, which is more usually called rotation.

6. (Geom.) The motion of a limit (that is, a point, line, or surface) about a point or line as its center or axis, in such a manner that a moving point generates a curve, a moving line a surface (called a surface of revolution), and a moving surface a solid (called a solid of revolution); as, the revolution of a right-angled triangle about one of its sides generates a cone; the revolution of a semicircle about the diameter generates a sphere.
7. (Politics.) The act of renouncing the authority of a government; a revolt successfully or completely accomplished; a fundamental change in political organization.

The violence of revolutions is generally proportioned to the degree of the maladministration which has produced them. Macaulay. ☞ When used without qualifying terms, the word is often applied individually, by way of eminence, to the revolution in England in 1688, when William of Orange and Mary became the reigning sovereigns, in place of James II.; to the revolution in the United States of America, beginning in 1775, and resulting in their independence; and to the revolution in France in 1789, commonly called the French revolution, the subsequent revolutions in that country being designated by their dates, as the revolution of 1830, or of 1848, &c.