The following glossary is adapted from the glossary provided by Planned Parenthood at https://www.plannedparenthood.org/learn/glossary.
Natural family planning: Fertility awareness-based methods of contraception. Inaccurately suggests that other methods are “unnatural,” which is why the term fertility awareness methods are preferred.
NGU or non-gonococcal urethritis: An inflammation of the urethra that is not caused by gonorrhea — often caused by chlamydia.
Nidation: Implantation, the attachment of the pre-embryo to the lining of the uterus, which begins about six days after fertilization and is complete in three to four days. The beginning of pregnancy.
Nipple: The dark tissue in the center of the areola of each breast in women and men that can stand erect when stimulated by touch or cold. In a woman’s breast, the nipple may release milk that is produced by the breast.
Nocturnal emission: A wet dream; sexual arousal and ejaculation while sleeping, which most often occurs among young men during adolescence or older men who are sexually abstinent.
Nocturnal orgasm: A sexual climax during sleep.
Nocturnal penile tumescence or NPT: Spontaneous erection during sleep that occurs among healthy men from birth through old age. NPT usually occurs about two or three times a night, lasting for a total of two or three hours.
Non-gonococcal urethritis: See NGU.
Nonoxynol-9: A chemical that immobilizes sperm that is used in most spermicides in the U.S.
Nonparous: Having never given birth.
Norgestrel: A kind of progestin used in some hormonal contraceptives.
NPT: See nocturnal penile tumescence.
Nulliparous: Having never given birth.
Nuptial: Regarding marriage.
Nuvaring: The brand name of a ring that contains hormones and is inserted in the vagina to prevent pregnancy. NuvaRing is a reversible hormonal method of birth control available only by prescription. Also called “the ring.”