Tribadism (/ˈtrɪbədɪzəm/ TRIB-ə-diz-əm)[1] or tribbing, commonly known by its scissoring position, is a lesbian sexual practice involving vulva-to-vulva contact or rubbing the vulva against the partner's thigh, stomach, buttocks, arm, or other body parts (excluding the mouth), especially for stimulation of the clitoris.[2][3][4] A variety of sex positions are practiced, including the missionary position.[4][5]
The term tribadism originally encompassed societal beliefs about women's capability of being penetrative sexual partners.[6][7][8] Women accused of having been penetrative during sexual activity were subject to ridicule or punishment.[6][8][9] In modern times, the term typically refers to various forms of non-penetrative sex between women. It may also involve vaginal penetration by use of the fingers, a dildo or double penetration dildo.[2][8]
It is analogous to frot, which is penis-to-penis contact between men.