Definition of "polymorphism" [pol•y•mor•phism]

• Biology The occurrence of different forms, stages, or types in individual organisms or in organisms of the same species, independent of sexual variations. (noun)
• Chemistry Crystallization of a compound in at least two distinct forms. Also called pleomorphism. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "What we were looking for was what we call a polymorphism—an unusual or abnormal form of a gene—that might prove to be associated with alcoholism."
• "In spite of the discovery that angiotensinogen (AGT) gene polymorphism is associated with essential hypertension, the genetics of this disease has remained poorly understood [58]."
• "This is called polymorphism where a sub-type can be substituted in any situation where a parent type is expected i.e. the object can be treated as an instance of the parent class."