The jamaharon was a sexual rite originating on the pleasure planet Risa.
One's desire to participate in jamaharon was indicated by the display of a horga'hn, a small statue which was the Risian symbol for sexuality. (TNG: "Captain's Holiday")
Jamaharon with Arandis was the direct cause of the death of Curzon Dax. (DS9: "Let He Who Is Without Sin...")