This is a Kabbalistic term for the serious violation of “wasting your seed” through masturbation or intercourse for reasons of pleasure rather than reproduction.
Written By Professor Gideon Aran
The widespread use among Haredim of terms with an affinity to such an exalted and central concept as the covenant to refer to bodily-sexual behavior that is considered deviant is telling. Against this background, the attempt to make invisible a phenomenon, which presumably takes place within the community, is particularly notable. The denial of bodily matters through semantic, rhetorical and other means does not allow for an open discussion or even elementary clarification of the subjects that, according to all indications, are bothersome to Haredim, both as individuals and as a collective.
Haredi rabbis monopolize the treatment of all sensitive bodily subjects, especially those connected to sex. They place the issue in the hands of their experts, and block access to alternative sources. Knowledge of sensitive body issues is manipulated and minimalized. This creates lacunae in precisely those areas where the need and desire for knowledge is greatest from the outset.
Taken from “Denial Does Not Make The Haredi Body Go Away Ethnography of a Disappearing (?) Jewish Phenomenon”, By Prof. Gideon Aran.