The original, priordial state of consciousness experienced when the consciousness is extracted from conditioning (defects, vices, traumas, etc).
"Hindu philosophy makes the division into four states of consciousness: sleep, dream, waking, and the state of absolute consciousness—turiya. G. R. S. Mead, in the preface to Taylor's translation of Plotinus (Bohn's Library) correlates the terminology of Shankarâchârya—the leader of the Advaita-Vedânta school of ancient India—with that of Plotinus: "The first or [original] spiritual state was ecstasy [turiya]; from ecstasy it forgot itself into deep sleep; from profound sleep it awoke out of unconsciousness, but still within itself, into the internal world of dreams; from dreaming it passes finally into the thoroughly waking state, and the outer world of sense." Ecstasy is the term used by Plotinus; it is entirely identical with the term turiya of Hindu psychology." -Tertium Organum, by P.D. Ouspensky, 
"Ecstasy is not a nebulous state, but a transcendental state of wonderment, which is associated with perfect mental clarity." - Samael Aun Weor, The Elimination of Satan's Tail
"Unquestionably, the Essence (the consciousness), through rigorous discipline, can escape from within the “I” (the ego); thus, it enjoys ecstasy. However, after such bliss, the Essence returns into the interior of the “myself.” Those who have become accustomed to ecstasy without having dissolved the ego believe that they have already reached liberation. They fool themselves by believing themselves to be Masters. They even enter into the submerged devolution." - Samael Aun Weor, Revolutionary Psychology
"Through many years of observation and experience, we have witnessed that authentic ecstasy is processed within mathematical laws and logic. Firstly, let us remember the unity of the mystical experience (which is a very appropriate name). During the state of sacred rapture, all mystics concretely feel something in common, a similar sense and an unmistakable tie of identical character. Secondly, let us consider the very interesting case of mystical language. By means of a judicious comparative study of religions, we have verified that mystics from different epochs speak the same esoteric language and use the same words. Without a doubt, this demonstrates to us the tremendous reality of mystical experiences. Thirdly, let us mention the astonishing concordance of the data that in a very intimate way connects mystical experiences with the intrinsic conditions of the world. From such conditions we can correctly identify the following: sensation of the unity of the whole, time—a very particular new sensation, the sensation of infinitude, pleasure or horror, the integral knowledge of the whole in one part, and finally, the unforgettable experience of infinite life and infinite consciousness." —Samael Aun Weor
“Ecstasy has seven degrees of power: The first is the fire that instructs and teaches us. The second is the Gnostic Unction, which is a soft, solar liquor, that when diffused throughout the Soul, teaches, corroborates, and prepares us in order to incarnate the Truth. The third is the mystical exaltation of the humble and sincere disciple. The fourth is the illumination. The fifth is the internal joy of divine sweetness that emanates from the precious fountain of the Holy Spirit. This joy is for those who have “continuous consciousness.” The sixth is the decapitation of the “I.” The seventh is the Venustic Initiation, the incarnation of the Son of Man within ourselves. Other degrees of contemplation and ecstasy exist, such as: rapture, liquefaction, bliss, jubilation, osculation, embracing, transformation, etc.” - Samael Aun Weor, The Aquarian Message
See also: Samadhi