What is the nature and meaning of development?

The act of developing or disclosing that which is unknown; a gradual unfolding process by which anything is developed, as a plan or method, or an image upon a photographic plate; gradual advancement or growth through a series of progressive changes; also, the result of developing, or a developed state., The series of changes which animal and vegetable organisms undergo in their passage from the embryonic state to maturity, from a lower to a higher state of organization., The act or process of changing or expanding an expression into another of equivalent value or meaning., The equivalent expression into which another has been developed., The elaboration of a theme or subject; the unfolding of a musical idea; the evolution of a whole piece or movement from a leading theme or motive.