haploid

1. Having the same number of sets of chromosomes as a germ cell or half as many as a somatic cell.
2. Having a single set of chromosomes.

An organism having haploid cells.

[From Greek haplous, single + –OID.]

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.

A haploid organism or cell.

Having half the number of chromosomes characteristically found in the somatic (diploid) cells of an organism; typical of the gametes of a species whose union restores the diploid number.

• h. karyotype — see haplotype.

The noun has one meaning:

Meaning #1: (genetics) an organism or cell having only one complete set of chromosomes

The adjective haploid has one meaning:

Meaning #1: (genetics; of a cell or organism) having a single set of chromosomes
  Synonyms: haploidic, monoploid
  Antonyms: diploid (meaning #1), polyploid (meaning #1)