The Sanskrit adjective kuṇḍalin means "circular, annular". It occurs as a noun for "a snake" (in the sense "coiled", as in "forming ringlets") in the 12th century Rajatarangini chronicle. Kuṇḍa, a noun which means "bowl, water-pot", is found as the name of a Naga in Mahabharata 1.4828. The Sanskrit feminine noun kuṇḍalī means "ring, bracelet, coil (of a rope)", and is the name of a "serpent-like" Shakti in Tantrism as early as the 11th century, in the Śaradatilaka.
What has become known as "Kundalini yoga" in the 20th century, after a technical term particular to this tradition, is actually a synthesis of Bhakti Yoga (devotion and chanting), Raja Yoga (meditation) and Shakti Yoga (the expression of power and energy)."[10][better source needed] However, it may include haṭha yoga techniques (such as bandha, pranayama, and asana), Patañjali's kriya yoga (consisting of self-discipline, self-study, devotion to God, dhyāna, and samādhi), visualization and meditation techniques of laya yoga (known as samsketas).
Laya may mean either the techniques of yoga or (like Rāja yoga) its effect of "absorption" of the individual into the cosmic. Laya yoga, from the Sanskrit term laya (meaning "dissolution", "extinction", or "absorption"), is almost always described in the context of other Yogas such as in the Yoga-Tattva-Upanishad, the Varaha Upanishad, the Goraksha Paddhati, the Amaraugha Prabodha, and the Dattatreya Yoga Shastra. The exact distinctions between traditional yoga schools are often hazy due to a long history of syncretism, hence many of the oldest sources on Kundalini come through manuals of the haṭha traditions, including the Hatha Yoga Pradipika and the Shiva Samhita. The Shiva Samhita describes the qualified yogi as practicing 'the four yogas' to achieve kundalini awakening, while lesser students may resort solely to one technique or another: "Mantra Yoga and Hatha Yoga. Laya Yoga is the third. The fourth is Raja Yoga. It is free from duality.