Definition of "polyploidy"

As they mature, the DNA is replicated several times but the cell does not divide, a condition known as polyploidy which allows cells to increase in size.

2011, Terence Allen, Graham Cowling, The Cell: A Very Short Introduction, Oxford, page 90

This propensity to polyploidy helps account for the diversity (and thus success) of flowering plants, in particular. It is also known that flowering plants sailed majestically through the life-destroying asteroid impact at the end of the Cretaceous period, which did for the dinosaurs and many other animals.

2014 June 28, “Double or quits”, in The Economist, volume 411, number 8893