pol·y·mor·phism 
(pŏl′ē-môrfĭz′əm)
(pŏl′ē-môrfĭz′əm)n.
1. Biology The occurrence of more than one form, as several alleles of a particular gene or winged and wingless forms of the same species.
2. Chemistry Crystallization of a compound in at least two distinct forms. Also called pleomorphism.
pol′y·morphic, pol′y·morphous adj.
pol′y·morphous·ly adv.