1.  A mental exercise peculiar to Yoga that encourages con­scious dreamless sleep, sometimes defined as "meditation-sleep," or "the moment of postponing sleep."

2.  Yogic sleep. A Tantric technique first introduced to the West by Paramahansa Satyananda Saraswati in the 1960s. Yoga Nidra involves the rotation of consciousness through the body and various visualizations. It produces a deep state of relaxation, in which the mind often remains quite alert.