Haploid

• the chromosome set with only one member of each chromosome pair
  Source: Jenkins, John B. 1990. Human Genetics, 2nd Edition. New York: Harper & Row
• single or reduced number of chromosomes in mature germ cells (gametes), or in the gametophyte generation of plants, in contrast to the diploid number; same as monoploid
  Source: Noland, George B. 1983. General Biology, 11th Edition. St. Louis, MO. C. V. Mosby
• Haploid is the quality of a cell or organism having a single set of chromosomes. Organisms that reproduce asexually are haploid. Sexually reproducing organisms are diploid (having two sets of chromosomes, one from each parent). In humans, only their egg and sperm cells are haploid.