polymorphism

Etymology

From poly- + -morphism.

noun

1. The ability to assume different forms or shapes.
2. (biology) The coexistence, in the same locality, of two or more distinct forms independent of sex, not connected by intermediate gradations, but produced from common parents.
3. (object-oriented programming) The feature pertaining to the dynamic treatment of data elements based on their type, allowing for an instance of a method to have several definitions.
4. (mathematics, type theory) The property of certain typed formal systems of allowing for the use of type variables and binders/quantifiers over those type variables; likewise, the property of certain expressions (within such typed formal systems) of making use of at least one such typed variable.
5. (crystallography) The ability of a solid material to exist in more than one form or crystal structure; pleomorphism.
6. (genetics) The regular existence of two or more different genotypes within a given species or population; also, variability of amino acid sequences within a gene's protein.
   Since 1990 they have found an entirely new role: they promise understanding of how and why our genes are all so different. They hold the key to human polymorphism. 1999, Matt Ridley, Genome, Harper Perennial, published 2004, page 137
   Some polymorphisms can be quite stable – so stable that they span the change from an ancestral to a descendant species. 2004, Richard Dawkins, The Ancestor's Tale, Phoenix, published 2005, page 63