Having multiple effects. For example: the cyclic AMP concentration in a cell will have a variety of effects because the cAMP acts to control a protein kinase that in turn affects a variety of proteins. ... (18 Nov 1997) ... 
Having multiple phenotypic expressions.Having multiple effects. For example, the cyclic-AMP concentration in a cell will have a variety of effects because the cAMP acts to control a protein kinase that in turn affects a variety of proteins.
Type: Term Pronunciation: plī′ō-trop′ik Definitions: 1. Denoting, or characterized by, pleiotropy. Synonyms: polyphenic
Pleiotropic: 1. Producing many effects. 2. Multiple effects from a single gene. For example, the Marfan gene is pleiotropic with widespread effects and can cause long fingers and toes (arachnodactyly), dislocation of the lens of the eye, and dissecting aneurysm of the aorta.
pleiotropic 1. Producing change in more than one trait; having several pehnotypic effects. 2. Pertaining to a phenotype characterized by multiple features due to a single genetic locus; polyphenic.