Mittelschmerz: The pelvic pain that some women experience during ovulation. (Ovulation generally occurs about mid way between menstrual cycles; hence the term mittelschmerz, which comes from the German words for "middle" and "pain.")
Monogamy: The practice of having sex with only one partner.
Neoplasm: An abnormal mass or colony of cells.
Nocturnal penile tumescence and rigidity testing: A test used to monitor erections that occur naturally during sleep. This test can help determine if a man's erectile problems are due to physical or psychological causes.
Non-coital behavior: Physically stimulating activity that does not include intercourse (such as sensual massage).
Non-infectious vaginitis: A form of vaginitis (irritation or inflammation of the vagina) that may result as a reaction to certain substances or chemicals, such as vaginal sprays, douches, spermicides, soap, laundry detergent, or fabric softener.
Non-seminoma: A type of testicular cancer that tends to be aggressive and occurs most often when men are in their 30s or younger. There are four types of non-seminomas: embryonal carcinomas, yolk sac tumors, teratomas, and choriocarcinomas. When these non-seminomas occur in combination, they are called mixed tumors.
Norplant: Six match-sized rubber capsules that are surgically implanted underneath the skin of a woman's upper arm. The sticks contain the hormone progestin, which releases slowly into the body and prevents pregnancy for up to five years. Norplant is no longer available in the U.S.
Omentectomy: The surgical removal of the fatty tissue covering within the abdomen.
Oncologist: A doctor who specializes in cancer treatment.
Oophorectomy: A surgical procedure in which one or both of the ovaries is removed.
Orchiectomy: A surgical procedure in which the doctor removes one or both testicles through an incision (cut) in the groin.
Orgasm: Sexual climax.
Oocytes (ova or egg cells): The female cells of reproduction.
Ovarian Cancer: An abnormal growth of tissue (tumor) that develops in a woman's ovaries.
Ovarian Cyst: A sac filled with fluid or a semisolid material that forms on or within one of the ovaries, the small organs in the pelvis that make female hormones and hold egg cells.
Ovary: A small organ in the pelvis that makes female hormones and holds egg cells which, when fertilized, can develop into a baby. There are two ovaries: one located on the left side of the uterus (the hollow, pear-shaped organ where a baby grows) and one on the right.
Paget's disease of the vulva: A condition in which cancerous cells are present in the skin of the vulva.
Pap smear: A screening test in which a sample of cells is taken from a woman's cervix. The test is used to detect changes in the cells of the cervix.
Paraphilias: Impulse disorders (mental illnesses) that are characterized by recurrent and intense sexual fantasies, urges, and behaviors. Paraphilias are considered deviant -- outside of acceptable patterns of behavior -- because they involve unusual objects, activities, or situations not considered sexually arousing to others.