- (of a species) having more than one form or type as a result of discontinuous variation: Cabbage, kale, broccoli, and cauliflower are all forms of a single polymorphic species.
- of or relating to a virus or other malignant code that has many forms, changing as it replicates: Polymorphic malware, which changes its identity up to 19 times a day to avoid detection while taking control of users' computers, has been successfully deactivated.
- of or relating to a substance that crystallizes into two or more forms having different structure but identical chemistry:The pharmaceutical under study here, at five structurally characterized forms, is one of the most polymorphic drugs known.
