n. The property of being polymorphous, or capable of existing in different forms; specifically, in crystallography, the property of crystallizing in two or more fundamental forms: thus, carbon crystallizes in isometric forms in the diamond, and in hexagonal forms in graphite.n. In zoology, difference of form, structure, or type; existence in, or exhibition by, a group of animals, as a species, genus, family, or order, of different types of structure; heterogeneousness.n. In botany, the comprisal of numerous definite or indefinite subtypes under a given type.