Impotence – (impotent adj.)
The inability to get or sustain an erection. See erectile dysfunction.

Incest:
Webster’s New World dictionary defines it as: Sexual intercourse between two people too related to marry. (however, this would not include anything other than intercourse, so, that is no longer a valid definition in most states in the USA, Canada and worldwide).

Saunders Dictionary of Medicine and Nursing defines it as:
Sexual activity between two persons so closely related that marriage between them is legally or culturally prohibited.

Infatuation:
Emotional or “foolish” love for another person.

Inhibited Arousal:
The inability to become sexually aroused or enjoy foreplay despite ones sexual desire.

Inhibition:
Feeling restraint due to fear or guilt.

Intercourse:
Sexual activity between two people in which insertion of the penis occurs. This includes vaginal intercourse, oral intercourse, and anal intercourse. It also means: communication or dealings among people.

Internalized Homophobia:
The fear of homosexuality within oneself.

Internal Sex and Reproductive Organs:
The organs inside the body that are responsible for producing, moving, and nourishing human reproductive cells. Because internal organs may be sensitive or respond to sexual stimulation, these organs are also called sex organs.

Intimacy:
The closeness and familiarity we feel as we share our private and personal selves with someone else.

IUD (Intrauterine Device):
A small device made of plastic or sometimes copper that may or may not contain a hormone. It is inserted into the uterus by a health care provider. Available only by prescription as a form of birth control. It is believed to prevent implantation of a fertilized egg.