The following glossary is adapted from the glossary provided by Planned Parenthood at https://www.plannedparenthood.org/learn/glossary.
Oocyte: An immature ovum, egg.
Oophorectomy: Surgical removal of an ovary.
Oral contraceptive: The birth control pill.
Oral herpes: An infection of the mouth with herpes simplex virus 1 or herpes simplex virus 2.
Orchitis: Inflammation of a testicle.
Orchiectomy: The surgical removal of one or both testicles. Usually performed to treat cancer or for genital reconstruction surgery.
Ortho Evra: Ortho Evra is a reversible hormonal method of birth control available only by prescription. Also called “the patch.”
Outer lips: See labia majora.
Ovarian cyst: A growth on an ovary, usually small, fluid-filled, and not cancerous. May cause abdominal pain or irregular periods. Most often resolves on its own.
Ovaries: The two organs that store eggs in a woman’s body. Ovaries also produce hormones, including estrogen, progesterone, and testosterone.
Over-the-counter: Available without a prescription.
Oviduct: Fallopian tube, one of two narrow tubes that carry the egg from the ovary to the uterus.
Ovulation: The time when an ovary releases an egg.