What is the X in X-mas?
1908, from German haploid (1905), from Greek haplos "single."
haploid hap·loid (hāp'loid')
Having the same number of sets of chromosomes as a germ cell, or half the diploid number of a somatic cell. The haploid number (23 in humans) is the normal chromosome complement of germ cells. n.
A haploid organism or cell.