adjective. Having four times the haploid number of chromosomes in the cell nucleus.

noun. A tetraploid individual.

adjective. having four times the haploid number of chromosomes in a cell nucleus

noun. a tetraploid organism

"The organization of the bdelloid genome is tetraploid, that is, instead of the more usual one pair of chromosomes, there are 2 pairs of similar chromosomes."

diploid  polyploid