(Sanskrit) Sexual abstention. See: What is Brahmacharya?
"Pseudo-esoteric and pseudo-occult reactionaries suppose they can awaken Kundalini by means of brahmacharya or forced celibacy. All initiates of authentic mystery schools know, through direct experience, that it is impossible to achieve the awakening and development of the seven grades of the power of fire without Tantric practices. There are two types of brahmacharya (sexual abstention): solar and lunar. Solar Brahmacharya is obligatory for all those who have already been born in the superior worlds with solar bodies, that is, for those who have left the Ninth Sphere. Lunar brahmacharya is practiced by many sincerely mistaken people, by many ignoramuses who have never worked in the Ninth Sphere, who have not built the solar bodies, who are without inner self-realization. The practice of lunar brahmacharya is harmful to those who have not built the solar bodies because they become charged with frightfully evil and terrible vibrations." - Samael Aun Weor, Light from Darkness