(Yoga Nidrā): The “yoga of [conscious] sleep.” In yogic literature, this term has a variety of meanings:

  1. The term Yoga Nidra is widely used in classical Hatha Yoga texts to denote the highest state of consciousness experienced while sleeping, prajna (direct understanding, discernment).
  2. Some contemporary yoga teachers employ the expression Yoga Nidra to designate a state of deep relaxation.
  3. The term is also applied to a complicated yoga posture (Yoga Nidra asana), which is executed by interlacing the legs behind the neck while resting on the back with the hands clasped behind the waist.
  4. In Hindu metaphysics and mythology, Yoga Nidra is the state of the god Vishnu at the end of a cosmic cycle, when the Universe is temporarily dissolved until Vishnu reawakens (the end of the cosmic cycle being the consequence of Vishnu’s sleep). This suggests the dissolution of any mental activity and an absorption in the highest Self.
  5. Yoga Nidra also means a state of absorption in undifferentiation. In Yoga Tadavali, Shankaracharya explained this as a condition of profound transcendence of the mind and the world: “When consciousness has transcended maya (delusion), when ego has become static, when senses are no more functioning, and when all communication between the mind and the senses has been cut, when I and you no longer exist for a period of time, Yoga Nidra starts.”