the act of unfolding or unrolling; hence, in the process of growth; development; as, the evolution of a flower from a bud, or an animal from the egg.-a series of things unrolled or unfolded.-the formation of an involute by unwrapping a thread from a curve as an evolute.-the extraction of roots; -- the reverse of involution.-a prescribed movement of a body of troops, or a vessel or fleet; any movement designed to effect a new arrangement or disposition; a maneuver.-a general name for the history of the steps by which any living organism has acquired the morphological and physiological characters which distinguish it; a gradual unfolding of successive phases of growth or development.-that theory of generation which supposes the germ to preexist in the parent, and its parts to be developed, but not actually formed, by the procreative act; -- opposed to epigenesis.-that series of changes under natural law which involves continuous progress from the homogeneous to the heterogeneous in structure, and from the single and simple to the diverse and manifold in quality or function. the pocess is by some limited to organic beings; by others it is applied to the inorganic and the psychical. it is also applied to explain the existence and growth of institutions, manners, language, civilization, and every product of human activity. the agencies and laws of the process are variously explained by different philosophrs.