What is De-evolution?

De-evolution definition and meaning on Dictionary terms:
any process of formation or growth; development: the evolution of a language; the evolution of the airplane.
a product of such development; something evolved: The exploration of space is the evolution of decades of research.
Biology. change in the gene pool of a population from generation to generation by such processes as mutation, natural selection, and genetic drift.
a process of gradual, peaceful, progressive change or development, as in social or economic structure or institutions.
a motion incomplete in itself, but combining with coordinated motions to produce a single action, as in a machine.
a pattern formed by or as if by a series of movements: the evolutions of a figure skater.

an evolving or giving off of gas, heat, etc.
Mathematics. the extraction of a root from a quantity.Compare involution(def 8).
a movement or one of a series of movements of troops, ships, etc., as for disposition in order of battle or in line on parade.
any similar movement, especially in close order drill.