"As bright as a million suns, as cool as a million moons, as subtle as a lotus fiber"
What is Kundalini ? This is a fundamental inquiry in the practice of Tantric Yoga, and yet in many ways so difficult to answer. Kundalini has had many meanings imposed upon her that to emphasize one is to risk excluding a whole wealth of understanding.
"She is the concealing and revealing aspect of Lord Shiva" says Swami Laksmanjoo, indicating the dynamic play of consciousness as both what is transcendent and immanent. She is Devatmashakti, the power of the Self; the self-reflective power of consciousness, vimarsa; the power of awareness to know itself. She is cit-Shakti, the energy of consciousness; the power to manifest and know the objects of experience. She is prana-Shakti, the power of the breath or life-force that sustains all of manifest reality; the energy underlying all of the senses. She is the source and maintainer of the three gunas - tamas, rajas and sattva and is thus known as Jagan-matha, the "Mother of the World". She is the source of all mantras, the garland of letters, indicating her association with speech as the 'vehicle' of intelligence. She is the highest sanctuary, the place of Divine inner pilgrimage, says the Vijnana-Bhairava-Tantra in praising the awareness of the flow of prana as a means to achieving liberation.
The only word that I have been able to think of which can encapsulate or approximate all of these varied meanings is "potential". In the same way that the notions of kinetic and potential energy exist in physics, in the meta-physics of spirituality there is the notion of Divine potential. The potential for the unmanifest, unlimited, transcendent aspect of Reality to become manifest, limited, immanent and vice-versa. The potential for consciousness to know Itself, through self-reflection. The potential of the life-force to sustain all of manifest existence or resorb it, as it flows 'upwards' through spiritual practice. The potential of the limited, individual consciousness to awaken to the fullness of it's Divine nature as that which is Universal, Eternal and Absolute.