Tribadism (/ˈtrɪbədɪzəm/ TRIB-ə-diz-əm)[1] or tribbing, commonly known by its scissoring position, is a lesbian sexual practice in which a woman rubs her vulva against her partner's body for sexual stimulation, especially for stimulation of the clitoris.[2][3][4] This may involve vulva-to-vulva contact or rubbing the vulva against the partner's thigh, stomach, buttocks, arm, or other body part (excluding the mouth).[2][3][4] A variety of sex positions are practiced, including the missionary position.[4][5]

Two women engaged in the missionary position of tribadism and rubbing vulvas, one of the various positions in which a woman rubs her vulva against her partner's body for the purpose of sexual pleasure.

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]