Definition from Oxford Languages ยท a noun - a form of sexual activity between women in which the genitals are stimulated by being rubbed against one another.
Tribbing" or "tribadism" comes from the Greek verb ฯฯฮฏฮฒฯ, which means "rub." Later, the words "tribas" (Latin) and "tribade" (French) were used to describe any woman who engages in penetrative or non-penetrative sexual activity with other women. to quote the 1843 text A Greek-English Lexicon, "a woman who practices an unnatural vice with herself or with other women." If you were accused of being a tribade, that would be bad news for your reputation. Scissoring is a colloquial umbrella term for all sorts of acts of tribadism.
A woman rubbing her clit pressing, grinding, humping against a lover's genitals, or any body part really a thigh, a foot, an ass, or any other body part, congratulations you've tribbed! Rubbing your wet cunt against another's hot body is both physically and visually pleasurable, whether you choose to call it "tribbing," "tribadism," "humping," "grinding," "scissoring," or something else naked or dressed.
Despite the word's sordid history, lesbians and bi-sexual women, have reclaimed "tribadism" and "tribbing" in recent decades to describe sex acts that involve genital rubbing, but definitions vary across sources. The Meriam-Webster dictionary defines tribadism as "a form of sexual activity between women in which the external genitalia are rubbed together," but in the 1988 book Sapphistry: The Book of Lesbian Sexuality, Patrick Califia includes a wider range of sex acts under the "tribadism" umbrella: "Tribadism is done by rubbing your vulva against your partner's mons veneris, hip, or thigh. Some lesbians also like to rub against their partners' buttocks or other parts of the body."