n. Change of form or structure; transmutation or transformation.n. A marked change in the form or function of a living body; a transformation resulting from development; specifically, in zoology, the course of alteration which an animal undergoes after its exclusion from the egg, and which modifies extensively the general form and life of the individual; particularly, in entomology, the transformations of a metabolous insect.n. In chem., that chemical action by which a given compound is caused, by the presence of a peculiar substance, to resolve itself into two or more compounds, as sugar, by the presence of yeast, into alcohol and carbonic acid.n. In botany, the various changes that are brought about in plant-organs, whereby they appear under changed or modified conditions, as when stamens are metamorphosed into petals, or stipules into leaves.n. In music, either the same as variation (see variation, 9), or that extension or transformation of a theme or subject which often appears in modern music in the progress or development of an extended movement. From Beethoven onward the recognition of the essentially plastic nature of musical ideas (see idea, 9) has steadily advanced and constitutes one of the salient characteristics of recent composition.