Heteromorphism refers to the occurrence of different forms or shapes between individuals of the same species. It is often used in biology to describe the differences in physical characteristics between males and females, or between different life stages of an organism. However, there are different terms that can also be used to express this concept. For instance, dimorphism refers to the existence of two distinct forms or types within a population, while polymorphism describes the presence of multiple variations or traits within a species. Other synonyms for heteromorphism include variation, diversity, and differentiation, which all point to the idea that organisms can exhibit different physical traits and forms.