(Sanskrit समाधि) Literally means “union” or “combination,” although in context it can have a dizzying number of meanings (see below). Its Tibetan equivalent means “adhering to that which is profound and definitive,” or ting nge dzin, meaning “To hold unwaveringly, so there is no movement.” Related terms include satori, ecstasy, manteia, etc. Samadhi is a state of consciousness characterized by clarity of perception and the absence of the ego. Samadhi is the state of consciousness sought by all schools of meditation.
"Ecstasy [samadhi] 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
"...On one given night, while in profound, internal meditation, I abandoned this illusory world of Maya. Thus, liberated from the shackles of this bitter existence, I submerged myself into Samadhi within the world of the Spirit. There is no better pleasure than feeling oneself as a soul detached from the body, the affections, and the mind." —Samael Aun Weor, Cosmic Teachings of Lama
Amongst meditation traditions, the word samadhi has been interpreted with great variety. One Sanskrit dictionary provides the following meanings for Samadhi:
"Samadhi: 1. Collecting, composing, concentrating. 2. Profound or abstract meditation, concentration of mind on one object, perfect absorption of thought into the one object of meditation, i.e., the Supreme Spirit (the 8th and last stage of Yoga). 3. Intentness, concentration (in general), fixing of thoughts. 4. Penance, religious obligation, devotion (to penance) 5. Bringing together, concentration, combination, collection. 6. Reconciliation, settling or composing differences. 7. Silence. 8. Agreement, assent, promise. 9. Requital. 10. Completion, accomplishment. 11. Perseverance in extreme difficulties. 12. Attempting impossibilities. 13. Laying up corn (in times of famine), storing grain. 14. A tomb. 15. The joint of the neck; a particular position of the neck. 16. (In rhetoric) A figure of speech. 17. One of the ten gunas or merits of style. 18. A religious vow or self-imposed restraint. 19. Support, upholding."
Therefore, it is important to note the context of the word.
In Yoga, Samadhi is the pinnacle of the steps of yoga. In the state of Samadhi, one is free of the limitations of the terrestrial bonds and can commune directly with the spiritual archetypes. Hinduism mentions many types of Samadhi: Jada Samadhi, Chaitanya Samadhi, Asamprajnata Samadhi, Nirvikalpa Samadhi, etc.
"There are seven Sadhanas of Yoga, namely Sat-Karma, Asana, Mudra, Pratyahara, Pranayama, Dhyana and Samadhi, which are cleansing of the body, seat postures for Yoga purposes, the abstraction of the senses from their objects, breath-control, meditation, and ecstasy which is of two kinds—imperfect (Savikalpa) in which dualism is not wholly overcome, and perfect (Nirvikalpa) which is complete Monistic experience–the realisation of the Truth of the Mahavakya AHAM BRAHMASMI—a knowledge in the sense of realisation which, it is to be observed, does not produce Liberation (Moksha) but is Liberation itself. The Samadhi of Laya Yoga is said to be Savikalpa Samadhi and that of complete Raja Yoga is said to be Nirvikalpa Samadhi. The first four processes are physical, last three mental and supramental. By these seven processes respectively certain qualities are gained, namely, purity (Sodhana), firmness and strength (Dridhata), fortitude (Sthirata), steadiness (Dhairya), lightness (Laghava), realisation (Pratyaksha) and detachment leading to Liberation (Nirliptatva)." - Swami Sivananda, Kundalini Yoga
In the Buddhist sutras and tantras the term Samadhi has a much broader application whose precise interpretation depends upon which school and teaching is using it. Samadhi is particularly significant in the Three Trainings:
Samadhi is state of consciousness free the painful conditioning of the mind (the “I,” desire, pride, envy, etc) and therefore the consciousness perceives reality objectively. Therefore, this is the only point of view that can see and understand the causes of suffering objectively, impartially, without confusion or obscuration.
Samadhi is usually considered by “Hinduism” as the highest stage of yogic accomplishment一the state of Mukti, or the final liberation from Sangsara. Buddhism, however, considers Samadhi as merely a higher state of mental concentration，having little to do with liberation or Nirvana. This is witnessed by the fact that the names of hundreds of different samadhis are listed in the Mahayana sutras.
The following are some of the basic characteristics of Samadhi:
1. In Samadhi the yogi’s mind is absorbed in perfect concentration on the object upon which he is meditating. It is a state of fusion, or unity, of the meditator and the object meditated upon.
2. In Samadhi the yogi always experiences an intensely blissful sensation, which is both physical and psychic. The intensity and profundity of this blissfulness is far greater than any bliss which the average human being has ever experienced. Allegedly it is many times greater than any rapture known in the sexual experience.
3. In Samadhi the yogi invariably experiences the presence of a great “illumination.” This is not a vision of a luminous nature, but the clear and bright aspect of the awareness of his own consciousness, an experience almost impossible to describe. All one can say is that the very universe itself seems to vanish into one great whole of transparency and light.
4. In an advanced stage of Samadhi no thought arises in the yogi’s mind, not even a thought of the object originally meditated upon. This is because every thought is a complete process, containing the stages of arising, subsisting, and dissipating; and this “perishable” process is the very thing that meditation aims to subjugate in order to bring the mind to a state of "no-thought This “thoughtlessness" of Samadhi is not torpidity or insensibility; it is a stabilized, illuminated awareness, devoid of any thought-in-motion. In short, human thought is awareness in motion, while Samadhi is awareness at rest.
Points (2), (3), and (4), namely, blissfulness, illumination, and “thoughtlessness,” are the three basic experiences of Samadhi. If any one of these is lacking, the Samadhi is incomplete.
5. Another major characteristic of Samadhi is the stoppage of breath. Without a complete cessation of breathing, the progressive thought-flow will never cease its perpetual motion. A number of different names have been used to designate Samadhi, one of them being “stopping the breath” (Chinese: chih ski), which unmistakably points to the fact that Samadhi is a state related to this condition. The reason for this common and very natural phenomenon of Samadhi is clearly expounded by Tantrism in its theory of the “Principle of the Identicalness of Mind and Prana" according to which every individual thought is brought into play by a particular Prana-in-action. If the Prana is pacified or halted, so is the mind, and vice versa. —G.C.C.Chang, The Practice of Zen (1959)
"Meditation is the esoteric discipline of the Gnostics. Meditation has three steps: concentration [dharana], meditation [dhyana], and samadhi. Concentration [dharana] means to fix the mind on only one object. Meditation [dhyana] means to reflect upon the substantial contents of that one object. Samadhi is ecstasy, mystical joy." —Samael Aun Weor, Igneous Rose
"The same energy that produces sexual sensations (when it is transmuted) then produces mystical ecstasy [samadhi]." —Samael Aun Weor, Alchemy and Kabbalah in the Tarot
"The mind of the student is prepared for Dharana, Dhyana, and Samadhi with the practice of Pranayama." —Samael Aun Weor, Kundalini Yoga
"When the mind is quiet and in silence — not only in the intellectual level, but in all and each one of the forty-nine subconscious departments — then the Newness emerges. The Essence, the consciousness, is unbottled, and the awakening of the soul, that is to say, the ecstasy, the samadhi, the satori of the saints occurs." — Samael Aun Weor, Magic of the Runes
“1. The Gnostic must first attain the ability to stop the course of his thoughts, the capacity to not think. Indeed, only the one who achieves that capacity will hear the Voice of the Silence.
“2. When the Gnostic disciple attains the capacity to not think, then he must learn to concentrate his thoughts on only one thing.
“3. The third step is correct meditation. This brings the first flashes of the new consciousness into the mind.
“4. The fourth step is contemplation, ecstasy or Samadhi. This is the state of Turiya (perfect clairvoyance). —Samael Aun Weor, The Perfect Matrimony
"The tantric practitioners from secret Tibet and sacred India practice the positive sexual yoga; this is to connect the lingam-yoni without the ejaculation of the ens seminis... This tantric connubial practice demands an absolute quietude and mental silence in order to avoid the tenebrous intervention of the pluralized “I.” Strong electromagnetic currents exuberantly flow in those instants of supreme voluptuousness; thus the couple enters into ecstasy or samadhi." —Samael Aun Weor, The Narrow Way
"Supreme meditation and absolute adoration takes us into ecstasy (Samadhi). Any master of Samadhi is an illuminated one. Nonetheless, we must know that illumination is one thing and that self-realization is another very distinct matter. A master of Samadhi (ecstasy) can unbottle the soul from the mind that is normally bottled up within the “I,” during a state of supreme adoration to experience the truth; but this does not signify the incarnation of the truth. After the ecstasy, the mind normally becomes bottled up within the “I,” and the mystic is left with his same tragic and painful life. Only by incarnating the truth is there a complete revolution within the human being." — Samael Aun Weor, The Aquarian Message
"Those who pretend to reach the final liberation without having previously eliminated the multiple undesirable psychic elements that we carry within our interior, walk on the path of error. Great hermits or anchorites were known to have lived in lonely caverns in the orient. Due to the fortitude of multiple disciplines, they reached ecstasy. However, they failed because they did not dissolve the ego. Those anchorites were accustomed to only momentarily taking the Essence, the Buddhi, out from the bottle. They then experienced Satori and Samadhi. Yet, following that mystic experience, they returned into the bottle like the genie in Aladdin’s lamp. Some of these Saints died in complete Mahasamadhi. Nevertheless, presently such Beings have returned as vulgar, ordinary people. They were skilled in Samadhi, yet they did not work on the ego; thus, the result is failure. To experience the Illuminated Void does not signify the Self-realization of the Illuminated Void." —Samael Aun Weor, The Gnostic Bible: The Pistis Sophia Unveiled