This appears in Greek and Latin satires as early as the late first century. The Greeks and Romans recognized same-sex attraction, but as any sexual act was believed to require that one of the partners be " phallic" and that therefore sexual activity between women was impossible without this feature, mythology popularly associated lesbians with either having enlarged clitorises or as incapable of enjoying sexual activity without the substitution of a phallus.
Because penetration was viewed as "male-defined" sexuality, a tribas was considered the most vulgar lesbian. The term tribade did not begin to refer exclusively to eroticism between women until Late Antiquity. In ancient Greek and Roman sexuality, a tribas, or tribade (IPA: /ˈtrɪbəd/ /tribad/), was a woman or intersex individual who actively penetrated another person (male or female) through use of the clitoris or a dildo.
The term tribadism derives from the Greek word τριβάς ( tribas), which in turn comes from the verb τρίβω ( tribō), "rub". It may also involve vaginal penetration by use of the fingers, a dildo or double penetration dildo. In modern times, the term typically refers to various forms of non-penetrative sex (or frottage) between women. Women accused of having been penetrative during sexual activity were subject to ridicule or punishment. The term tribadism originally encompassed societal beliefs about women's capability of being penetrative sexual partners. A variety of sex positions are practiced, including the missionary position. 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). Tribadism ( / ˈ t r ɪ b ə d ɪ z əm/ TRIB-ə-diz-əm) 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. 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.