The state or philosophy of having a closed, committed relationship involving more than two people.

A committed relationships involving more than two persons in which all sexual activity is confined to the group.

(poly=many; fidelis=faithful) The state or practice of sexual exclusivity among a group of three or more primary partners. A closed group marriage emphasizing equal primacy of all relationships.

n : a group in which all partners are primary to all other partners and sexual fidelity is to the group; shared intent of a lifelong run together. More primary partners can be added with everyone's consent. The term was coined by the Kerista commune.

A polygamous relationship in which each participant restricts their sexual behavior to others within the established group.

Polyfidelity, is a form of polyamorous group marriage wherein all members consider each other to be primary partners and agree to be sexual only with other members of this group. This term originated within the Kerista Village commune in San Francisco which practiced polyfidelity from 1971–1991. Kerista also expected all members of a polyfidelitous group to be sexual with all other members (within bounds of their sexual orientations), but this aspect of polyfidelity is not always expected today.