1. [adj]  having or occurring in several distinct forms; "man is both polymorpphic and polytypic"; "a polymorphous god"
2. [adj]  (biology) relating to the occurrence of more than one kind of individual (independent of sexual differences) in an interbreeding population; "a polymorphic species"
3. [adj]  (chemistry) relating to the crystallization of a compound in two or more different forms; "polymorphous crystalzation"

polymorphism

1. Describes a substance that can take on several different shapes; specifically, it refers to a protein which can be coded by several different sequences; these variations do not ruin the protein's function.
2. Having more than two distinct forms.