Noun
endoreduplication (countable and uncountable, plural endoreduplications)
(genetics) The replication of chromosomes without mitotic cell division.
Even in diploid organisms, many somatic cells are polyploid due to a process called endoreduplication where duplication of the genome occurs without mitosis (cell division). Source: Internet
Endomitosis is a variant of endoreduplication in which cells replicate their chromosomes during S phase and enter, but prematurely terminate, mitosis. Source: Internet