[rev.o.lu.tion] n [ME revolucioun, fr. MF revolution, fr. LL revolution-, revolutio, fr. L revolvere to revolve] (14c) 1 a (1): the action by a celestial body of going round in an orbit or elliptical course; also: apparent movement of such a body round the earth (2): the time taken by a celestial body to make a complete round in its orbit (3): the rotation of a celestial body on its axis b: completion of a course (as of years); also: the period made by the regular succession of a measure of time or by a succession of similar events c (1): a progressive motion of a body round an axis so that any line of the body parallel to the axis returns to its initial position while remaining parallel to the axis in transit and usu. at a constant distance from it (2): motion of any figure about a center or axis "~ of a right triangle about one of its legs generates a cone" (3): rotation 1b
2. a: a sudden, radical, or complete change b: a fundamental change in political organization; esp: the overthrow or renunciation of one government or ruler and the substitution of another by the governed c: activity or movement designed to effect fundamental changes in the socioeconomic situation d: a fundamental change in the way of thinking about or visualizing something: a change of paradigm "the Copernican ~" e: a changeover in use or preference esp. in technology "the computer ~" "the foreign car ~" syn see rebellion