Tribadism

Tribadism or tribbing, commonly known by its slang name scissoring position, is a sex act in which a woman rubs her vulva against her partner's body for sexual stimulation, especially for ample stimulation of the clitoris. This may involve female-to-female genital contact or a female rubbing her vulva against her partner's thigh, stomach, buttocks, arm, or other body part (excluding the mouth). A variety of sex positions are practiced, including the missionary position.

The term tribadism is usually used in the context of lesbian sex, and originally encompassed societal beliefs about women's capability of being penetrative sexual partners. Women accused of having been penetrative during sexual activity were subject to ridicule or punishment. In modern times, the term typically refers to various forms of non-penetrative sex (or frottage) between women. It may also involve vaginal penetration by use of the fingers, a dildo or double penetration dildo, or refer to a masturbation technique in which a woman rubs her vulva against an inanimate object such as a bolster to achieve orgasm.

The term tribadism derives from the Greek word τριβάς (tribas), meaning "a woman who practices unnatural vice with herself or with other women", which derives from the verb τρίβω (tribō), "rub". In ancient Greek and Roman sexuality, a tribas, or tribade, was a woman or intersex individual who actively penetrated another person (male or female) through use of the clitoris or a dildo. The term tribade did not begin to refer exclusively to eroticism between women until Late Antiquity.

In addition to the scissoring position, which involves the partners interlocking their legs in a position similar to the shape of scissors and pressing their vulvas together, tribadism may involve a missionary position, a woman on top position, a doggy style position or others, or simple movement of the woman's vulva against her partner's thigh, stomach, buttocks, arm, or another body part. Vaginal penetration by use of the fingers or by use of a dildo may be accompanied, and so sometimes "mutuality and reciprocation tend not to be the main objective, although satisfaction for both partners through different means most definitely is its aim".