pleiotropy Syllabification: (plei·ot·ro·py)Pronunciation: /plīˈätrəpē/Definition of pleiotropy noun Genetics the production by a single gene of two or more apparently unrelated effects. Derivatives pleiotropicPronunciation: /ˌplīəˈtrōpik, -ˈträpik/ adjective pleiotropismPronunciation: /ˌplīˈätrəˌpizəm/ noun Origin: 1930s: from Greek pleiōn 'more' + tropē 'turning'pleiotropy in other Oxford dictionaries Definition of pleiotropy in the British & World English dictionary