Ĕv′o-lū′tion, n.

n. [Lat. evolutio, from evolvere; Fr. évolution, Sp. evolucion, It. evoluzione.]

1. 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.
2. A series of things unrolled or unfolded. “The whole evolution of ages.” Sir T. More.
3. (Geom.) The formation of an involute by unwrapping or unwinding a thread from another curve as an evolute. Hutton.
4. (Arith. & Alg.) The extraction of roots;—the reverse of involution.
5. (Mil. & Naval.) A prescribed or regular movement of a body of troops, or of a vessel or fleet; or any movement designed to effect a new arrangement or disposition of forces in the most advantageous and effective manner.

Those evolutions are best which can be executed with the greatest celerity, compatible with regularity. Campbell. 6. (Physiol.) That mode of generation in which the germ is held to pre-exist in the parent, and its parts to be developed, but not actually formed, by the procreative act. Dunglison.