Nirvikalpa samadhi

Nirvikalpa is a Sanskrit adjective with the general sense of "not admitting an alternative", formed by applying the contra-existential prepositional prefix ("away, without, not") to the term ("alternative, variant thought or conception").
Usage

In our Hinduism, when used as a technical term in Raja Yoga, the phrase samādhi refers to a particular type of samādhi that Heinrich Zimmer distinguises from other states as follows:

'''', on the other hand, absorption without self-consciousness, is a mergence of the mental activity in the Self, to such a degree, or in such a way, that the distinction of knower, act of knowing, and object known becomes dissolved — as waves vanish in water, and as foam vanishes into the sea. The difference to the other samadhis is that there is no return from this samadhi into lower states of consciousness. Therefore this is the only true final Enlightenment.

Paramahansa Yogananda describes this degree of samadhi as follows:

In the most advanced state, nirvikalpa samadhi, the soul realizes itself and Spirit as one. The ego consciousness, the soul consciousness, and the ocean of Spirit are seen all existing together. It is the state of simultaneously watching the ocean of Spirit and the waves of creation. The individual no longer sees himself as a "John Smith" related to a particular environment; he realizes that the ocean of Spirit has become not only the wave of John Smith but also the waves of all ofter lives. In nirvikalpa the soul is simultaneously conscious of Spirit within and creation without. The divine man in the nirvikalpa state may even engage in performance of his material duties with no loss of inner God-union.