polyploid
an organism with more than twice the basic number n of chromosomes of the ancestral species in its vegetative cells —note a cell, tissue, or organism having three sets (3n) is called triploid, four sets (4n) tetraploid, and six sets (6n) hexaploid —see aneuploid, chromosome number, diploid, haploid, mutation, xeniaThis definition last updated 10/27/2008