noun Genetics.

the phenomenon of one gene being responsible for or affecting more than one phenotypic characteristic.

Origin of pleiotropy

First recorded in 1935–40; pleio- + -tropy
Related formsplei·o·trop·ic [plahy-uh-trop-ik, -troh-pik] /ˌplaɪ əˈtrɒp ɪk, -ˈtroʊ pɪk/, adjectiveplei·o·trop·i·cal·ly, adverb Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Word Origin and History for pleiotropy

1921, from German pleiotrop (1910), from Greek pleion "greater in quantity, the more part, very many," (see pleio-) + trope "turn, turning" (see trope). Related: Pleiotropic; pleiotropism.

Online Etymology Dictionary, © 2010 Douglas Harper